Toyota Prius, other hybrid stuff, and related links
For easy reference, this file is
Last update: 110610
Link stability is completely subject to each provider's whim.
There is now a section about the
generation III Prius, new for 2010.
Printable one-page "tech info" flyer pointing to this site. Geeky. Uses
one of Toyota's old graphics overlaid with the fundamental HSD design
diagram from one of the original Prius-related patents.
Quick-n-dirty tag index
Informational / howitworks
Service and teardowns
The 3rd-gen Prius
Forums and newsgroups
Dealers / vendors
Traffic and fuel economy
Informational / howitworks and other helpful pointers
An easy way of forcing the engine in a Prius to start and idle,
for inspection or diagnosis purposes. Works around the
This method bears no risk to the transmission, whereas the more
complex "inspection mode" may if misused.
Some really well-designed presentations and discussion about how
the Prius works, especially the planetary drivetrain.
Minor rework of Graham's nomograph, extended to higher RPM [particularly on
the negative side, reflecting high-speed coasting], and with a schematic of
the planetary gearset thrown in.
One perceptive and knowledgeable owner's long-time logs, photo galleries,
handouts/flyers/cards, link-nests, and lots of information. Almost every
other Prius-related site out there points to him.
Several useful FAQs and checklists hosted by Tom Stangl.
Another tech rundown on the Prius [with help from Graham] from a New Zealand
car dealer that specializes in hybrids.
Mirror of Toyota's Hybrid Synergy Drive description [two parts]. Was
originally hosted at
until some destructive asshole hacked the site and the whole "files" section
got zorched. Fortunately, I had a backup copy, so here it is.
The original "EV-button" hack description. [1.4Mb]
Basic explanations of how the Prius works, and debunking of several
Various shots of cutaway Prius transaxles; #4 is the second-gen design.
Wayne Brown, one of the seminal Prius hackers, maintains a good info
site that only *hints* at some of the amazing analytical work he's done.
He's also one of the foremost "extra batteries" experimental pioneers.
[a rework of what was
which seems to have vanished in the meantime]
The five stages of Prius hybrid operation. Describes operational
phases that the HSD system passes through while warming up.
In-depth explanation of the "B" shift-selector position and its
purpose, uses, and quirks.
Description of high-speed "glide" mode that uses no fuel, and how to find it.
Another in a series of "prius subtleties, because people always ask" articles.
The answer to a common complaint about Prius brakes feeling "grabby" or
otherwise strange, particularly when nearing a stop at about 7 mph.
The fix? Throw it in neutral to disable regen during a couple of stops,
and the stuff scrapes right off.
Test-bench exploration of why regenerative braking can work at low motor
RPM and still produce sufficient voltage to charge a high-voltage battery.
A large and well-maintained collection of Prius articles, reviews,
sites, news, etc by Mr. J. Kash, a history teacher.
Power output, efficiency, and [theoretical] BSFC curves for the Prius internal
combustion engine [ICE], taken from various sources. Illustrates the effects
of optimal loading, about where that occurs with the THS, and how the throttle
control algorithm makes every effort to optimize it.
[!oops, broken link!
Here's a backup copy]
shows a more typical BSFC map [from
this report, which seems to have gone missing now] and the options for
obtaining various fractions of engine output power. This places the
sweet-spot around 1800-2000 RPM at high shaft load, which is also about
the real-life truth for the Prius engine albeit at somewhat lower torque.
Animated illustration of how the original Atkinson variable-displacement
engine work [and many other types -- great site]
Illustration of Toyota's Atkinson/Miller cycle, showing how they also
optimize variable intake valve timing as well. Several running modes shown.
Range 4 is where you want to be on the highway.
Investigation into Prius variable intake valve timing at highway speeds,
smashing various prior theories about operation, and general details on
how crank and cam sensors work. A veritable blizzard of scope traces.
A really good paper/presentation on different "hybrid synergy"
drivetrains and rationale.
NHTSA/DOT starter interlock and transmission safety standards NPRM
for hybrids, that explains the whole rationale about "creep" force
and directional cueing for a driver.
Some more general hybrid news and forum sites.
Alt Wheels, for a while the largest yearly Boston-local conference/show on
alternative fuels, sustainable transportation and infrastructure, and lots of
cool vehicles displayed on the MOT
lawn. For '06 and beyond, it has moved to Boston City Hall Plaza. Some
of us did a fun group booth in '07.
The "Naked Prius" tech exhibit takes top honors at AltWheels 2005!
Shows the leadup and easily-removed parts, too.
Prius discussions at Toyoland, a Toyota enthusiast site [run by Allpar]
In the "john with numbers" group of contributors, another good general
site about all generations of the Prius. Has a good chunk of early info
about the 2010 model. Mostly in Dutch, though.
Tons of good auto-tech info with heavy Toyota emphasis. In fact, all of
autoshop101.com is very useful -- recommended reading for pros and weekend
warriors alike. A notable item is "Understanding Toyota Wiring Diagrams".
Much of this is original Toyota hybrid tech training material, evidently
now released to the general public without subscription cost.
The Panasonic-EV website, recently renamed to "Primearth" [which conveniently
didn't change their domain name!] detailing ongoing improvements in their
NiMH battery modules. They manufacture the
Prius HV pack modules,
as well as batteries for several other vehicles including minivan
form-factor ones that after five years, are inexplicably STILL not sold
into the US market.
Details on the [2rd-gen] Prius 12 volt battery -- dimensions, type, the
mounting area, voltage regulation, and quiescent drain. Please contribute
to the knowledge here -- there has *got* to be a good aftermarket unit
that will fit in this space and not cost $160 from the Toyota dealer!
UPDATE -- there is one, see the second part of the page for the answer.
was: priuschat.com/index.php?showtopic=22210 until Jan 2008]
A thread revealing the existence of a means to completely reset the Prius'
list of valid keys and program new ones, WITHOUT having to swap out any
ECUs. Works through the THHT, aka Vetronix "Mastertech MTS3100" scantool.
A FAQ that some people tried to put together on a wiki, but not only gets
a lot of stuff wrong, it's got the typical wiki problem -- no control over
misinformation and flat-out vandalism. Take with a large grain of salt.
Open wikis don't entirely suck, *people* suck.
Service and teardowns
Taking things apart, reverse-engineering, diagnosis, and repair hints.
[backup copy here]
U.S. government-funded studies of the Prius at Argonne and Oak Ridge.
Useful data, and really drives home how Toyota is completely kicking
our asses from an engineering standpoint because we couldn't figure
out how to build it ourselves.
The 890029.PDF link is a more final report, and includes several good
pictures from inside the Prius inverter and driveline. If it turns
up moved or missing from the OSTI site, use the local copy here.
A deep investigation into the Prius inverter, covering how it's assembled
and beginning extensive analysis of the electronics. Ongoing project.
Some shots of a disassembled 1.5L engine block during a resealing job.
Technical training information, primarily on the Prius but also covering
basic 3-phase motors and inverters, with pointers to other hybrid training
info freely available on the net. The Prius material alone can easily fill a
full-day seminar, or more if coupled with hands-on demos and work in a shop.
If you're not up to speed on hybrid service yet, here's where to look!
What service items does your Prius really need, and when? The dynamic duo
of Galaxee and her Dear Husband set it all out for you here. Beware of
the "upsell" when you don't need it!
Changing the PSD transaxle fluid in an '04, using the seekrit undocumented
top fill plug. Shows shifting the inverter around without draining its
coolant, to access items under it. Some other minor but useful maintenance
items are discussed here too.
More maintenance items to take care of as the '04 hits the 100,000 mark and
beyond, including extensive discussion of coolants and brake fluids and their
expected lifetime vs. their real-life condition at this point. The inverter
cooling pump is also changed, as it's commonly found to start wearing out
around the same time. An engine-temp fakeout is finally installed and the
MAF and various other parts are inspected and commented on.
Discussion/pictorial of Prius brake cleaning and service, not that it's
nearly as necessary as in non-hybrid cars! But yearly cleanout and particular
attention to keeping the front caliper slide-pins free to move is a good idea
nonetheless. Includes details on how the rear drums self-adjust the shoes.
-- seems to have fallen victim to domain squatting,
so here's a backup copy:
An excellent guide to carefully removing the dashboard panels and MFD
to get to and behind the stereo. If you're going to do work around
the dash in general, read through this first. And boycott Dotster when
shopping for domain registrars.
Finding and fixing a common fault in the display screens of some '04 and
'05 Priuses. Requires fairly small-scale work, but should be within the
capability of most electronics hobbyists.
Details on removing and disassembling the "body ECU" and main connector
block from under the dashboard.
How to fix a factory-assembly problem that can cause damage to the motor
control harness, due to a starter blockoff-plate fitted backwards that
places a sharp metal edge right next to some very important wiring.
Tail light assembly removal, with pictures. Some of the inner trim needs
to come out first, then it's two bolts.
Exploration inside the Prius battery box, at six years and 130K miles, to
check for any potential [!] problems and play with high voltage and hybrid
system isolation. Includes a good look at the cooling fan hardware, and
a brief dip into what's inside the brake reserve power-supply box as long
as we're fooling around in the back of the car.
An expose' of the gas tank bladder, done by Galaxee's hubby after he replaced
a tank that had been hopelessly overfilled to the point of ruining the
Backup hosted copy of Doug Schaefer's document on renovating the NHW11
(Classic) accelerator pedal after it starts exhibiting the sluggishness
"big hand" syndrome. The NHW20 uses non-contact Hall-effect sensors and
is thus immune to this problem.
A look inside the electric coolant pump that runs the separate radiator
loop for the Prius inverter and motors, and a best-guess theory on why
these things fail somewhere around 100K miles.
Dead link. Alldata USED to have a nice non-subscription mirror
of Toyota TSBs,
especially ones that describe known problems/issues/fixes with certain
model-year cars. They've apparently gone mercenary and taken it down
in favor of the new
"alldatadiy" structure. Do WHAT yourself, huh? Nice
way to help the community.
However, there's still ...
NHTSA database of all TSBs and SSCs/recalls. Drill down through the forms to
find info on the Prius or any other car -- the database is QUITE extensive.
You can at least see what the TSBs are about, although getting the actual
documents costs money and asks for personal information. My tax dollars
paid for this nonsense?!
Florian Steiper's failed 2002 transaxle, which he disassembled to reveal some
burnt motor windings. There have been a few instances of this in 2001 and
2002 "Classic" Priuses, and the jury is still out on whether this is from an
inherent design flaw, overlooked maintenance, or just some unlucky owners.
Where to find some manuals, parts, and lists of dealers. Script-based,
may not work in all browser environments.
Removal and cleanout of the Prius driver's door lock cylinder, which is
much easier than expected and does NOT involve extensive door panel
Gordon Jennings writes on proper spark plug selection, and how to read
an engine's running conditions from the condition of the plugs.
A pictorial essay on the Prius electric throttle body, how to test it,
how to do routine service
on the mechanism without complete removal from the car.
How to adjust valve clearance on the 1NZ-FXE engine, by measuring and
replacing the little cam-follower buckets. Should rarely be necessary,
however -- Prius engines generally have a history of going multiple
hundred thousand miles with virtually no mechanical service.
The innards of the dash-lights "rheostat" in the Prius. It's actually
a low-side PWM unit with a couple of other control leads that tells
the MFD to go full-bright or dim. A proper LED brightness booster for
the frequently complained-about steering wheel button backlight would have
to deal with this as either a control input or its negative supply rail.
Nice description of various maintenance items from Art's.
Links to some ASA articles on servicing hybrids; good info
for both independent auto techs and shadetree wrenchers. Slightly out
of date, since it seems to mostly deal with the Classic prius.
International Automotive Technician's Network, a large forum where auto
techs hang out and swap advice, ideas, rants, etc. Subscription needed
for most of the areas but there is some free info available and the freely
viewable day-to-day question/answer summaries can be interesting.
The innards of the Coastal ETech cruise-control based EV-mode switching
circuit. Uses a micropower comparator and accumulates enough charge
from the inputs to fire a transistor and ground the pin. Easily enough
visual info to reverse-engineer your own clone, although I personally
like the immediacy and simplicity of a straightforward pushbutton.
Also see the
nest and Prius-camping page below for details on the A/C blower
Archived newsletters from the Massachuestts vehicle inspection and testing
administration, geared toward inspection personnel. Often covers several
interesting OBD-II and emissions-monitoring diagnostic topics.
The third generation
Articles and information relating to the 2010 and later model Prius, which
had quite a bit of buzz surrounding its introduction in early 2009.
Canadian Driver's "first look" article: lots of detail, but what they say
about "B" mode about halfway through is hopelessly wrong. We could easily
live without all the inane comments tacked on at the end, too.
Followup on the 2010 from Canadian Driver, a bit of rehash but from a slightly
different viewpoint. Same caveat about the commentary from the great unwashed.
Photo gallery of test-driving the 2010 in Orlando.
The main Priuschat thread on the 2010. There are several other 2010-related
areas including maintenance and technical discussion on Priuschat, which also
served as a semi-official info-clearinghouse during the launch. Around that
time Toyota's marketing arm finally started actually *participating* in some
of the forums, after years of silent snooping.
The official 2010 Prius introduction pictures, from Toyota and hosted by
Danny at Priuschat.
John Voelcker of High Gear Media tried to fill 30 days' worth of 2010 Prius
review, but seems to have petered out by about day 9.
The "hybrid system indicator" display screen introduced in the 2010 Prius
is analyzed and compared to the earlier model cars, and some best-efficiency
usage hints are explained. Warp stealth is now easy to find and maintain
without extra instrumentation!
A Priuschat thread on reverse-engineering various CAN / OBD-II information
in the third-gen Prius. The real meat begins when "frenchie" chimes in
around message 27, and gets quite interesting in subsequent pages. It only
took six months or so for the community to sniff enough network traffic
to generate a useful set of Xgauge progamming for the 2010 model, but
it is naturally an ongoing process.
Bernie discourses on the battery layout in the 2010, and whill hopefully
add more info to this page as he learns of it.
Research toward the most streamlined way to install an engine block heater
in the 2010+ Prius, which is a little more complex than the second-gen.
General Prius / hybrid articles
Events, stories, news clips, videos, and random items of interest
Article on the Canadian cab driver who went over 200,000 miles in his first
Prius and continues to rack up more miles than just about anyone else.
110 MPG and a 1400-mile tank in a stock Prius: A small bunch of dedicated
crazy geeks spent a weekend in Pittsburgh to shatter previous mileage
records. These forum threads detail the whole "Marathon" story and point
to related items. Extreme pulse-n-glide.
Various press about hypermiling and/or Hybridfest, summer 2007.
Observations on a Prius "sweet spot" engine efficiency range, yielding
improved MPG at mid and higher speed ranges with proper application.
with some refinements, instrumentation notes, and a long-term perspective
on it all.
"Godfather of the Hybrid" : article from Caltech's Engineering & Science
magazine on Victor Wouk and his early research into electric propulsion
and mixed gas/electric systems.
Article about the introduction of the 2004 Prius, noting the many
design improvements and Toyota's business model for production.
Prius land speed record tests at Bonneville, by a team from Toyota
and Car & Driver.
Car & Driver review of the 2004 Prius.
Birth of the Prius, an article on development history and market
Fun article on hybrid service and features by the folks at Art's
Automotive, a service shop in Berkeley CA that loves hybrids.
Russell Frost's blog, news, and other items-of-interest site. Also the
guy behind frostimaging.com. For a while he was reviewing and selling
various portable GPS units, too.
The "creative lab scope technique" page, endorsing out-of-the-box thinking
when diagnosing automotive problems with scopes and similar equipment.
Sign-up required for the actual articles. There is also a forum area.
Article about synthetic oil and engine life.
Good reasons to run higher tire pressure in police vehicles, as well as
[this used to be "...article.jsp?siteSection=19&id=27281" which went
dead, but there's an obvious pattern which should work if you're looking
for any other officer.com articles. If the above link goes invalid again,
here is a backup copy without the original
A serious WARNING about inferior aftermarket valve stems that could crack
and leak in a relatively short time. Affects all cars, especially newer
ones that are supplied with higher-pressure tires.
Good info about many battery technologies, types, charging, safety, etc.
A pictorial essay about how well a Prius handles large loads, especially
with mods to distribute the weight better.
Interview with Ron deLong, inventor of the Scangauge.
A rant engendered by a rather horrendous "web experience" at Toyota's
service-manuals subscription site.
Carolyn Coquilette [Lusciousgarage] on Prius accelerator pedals, floor
mats, and the elusive "unintended acceleration" problem.
Good explanation of ABS, traction control, and vehicle stability control.
Part technical rundown, part opinion piece on the whole "sudden
unintended acceleration" and 2010 Prius braking issues dust-up. Tries
to cut through some of the political theatre going on with this.
==> And guess what? A year later, the NHTSA concludes that
the vast majority of such incidents are
driver pedal misapplication. Case closed.
The hatch area of a third-gen Prius turns easily into a cozy and relatively
private sleeper-berth, and there's even a way to run the ventilation system
on very low power without needing the rest of the car turned on.
Hobbit's running Prius diary/blog/whatever. Points to a number of the
mods and hacks listed here, and places them in a back-story and timeline.
In perpetual flux, and often out of date with the present. If nothing
else, it describes the purchase rationale and process when this whole
PHPbb-based discussion forum; quite active. Has technical areas and
downloadable FAQs and a strong overall sense of community. Using the
forum search engine can be quite productive, and can be done by anyone
without having to sign up first.
[IMPORTANT NOTE regarding Priuschat:
Since its changeover from IPB to vBulletin in Dec 2007 and the
associated database migration, many of the old thread numbers have
changed, causing externally and internally linked threads and
articles to be broken now. They are still in there somewhere
and you can still do searches, they'll just turn up as different
topic numbers anywhere from about 700 to 1400 numerically lower than
the corresponding old ones. No idea if/when this will be fixed.]
Similar to priuschat, but a more obfuscated presentation.
Also has a good knowledge-base section.
Where a lot of the "hypermilers" hang out. Get your high-mileage technique
pointers here -- for any vehicle, not just hybrids! No gimmicks, no
cow-magnets or hydrogen bubblers or gas pills, just solid and proven
results simply from improved and significantly safer driving skills.
LiveJournal community for Prius discussions.
WARNING: Yahoo-group sites generally want cookies enabled.
Most of these groups have publicly-accessible archives, such that you can
read all the postings without needing a Yahoo account or signing up for the
group. Some of the groups have a /files/ section for uploaded FAQs and
pictures and such, but apparently those are accessible only to Yahoo
accounts that are actually also members of the group, and nobody's figured
out how to make the /files/ sections publicly readable. Some of the
information is duplicated elsewhere that is more accessible.
One of several Prius groups, general topics, open archives, very active.
Another of several Prius groups -- general topics, open archives.
Covers 2004 - 2007 and beyond; the group name tends to track the
current model year [in case this link falls out of date].
*Note: there was a precursor group, 2004-prius [not 2004_prius],
but that's been buried by spam and nobody uses it anymore.
Non-public archives but a group well worth simply joining if terms like
"IGBT half-bridge" and "crankshaft reluctor" get you hot. Many of my own
ramblings and experiments have crossed this group over the years, and are
findable in the archives.
Banter about the CalCars pluggable-hybrid prototype, from inception of
the project. Open archives. Good techie content here and there.
One of the earlier modder groups; fairly inactive now.
Northeast-oriented list. Fairly inactive; its members are too busy
hanging out on all the other lists and forums.
Owners' group for the ORIGINAL (NHW10 model) Prius in Japan, and some
Aus/NZ exports, 1998-1999. Many are still on the road.
An attempt to route around the pervasive Flash and scripting damage that
Toyota insists on shoving down web visitors' throats, and actually point to
the real information. This could change next week; no guarantees.
Technical Information System [TIS], where online service manuals reside
[on a paid subscription basis]. An absolutely horrendous site design that
relies way too heavily on scripting bells-n-whistles, and assumes that
everyone happily runs IE with no security turned on.
Techstream, the next generation of Toyota's dealer scantool that integrates
OBDII and OEM diagnostics with internet links to Techinfo via wireless
infrastructure in and around the service bay. Ruggedized laptop-based.
Rumored to be based on an OTC/SPX scantool product rebranded for Toyota.
Vetronix has lost their long-time hold on this market.
Emergency response guides for various Toyota hybrid and alt-fuel vehicles,
aimed at teaching first-responders about hybrid vehicle rescue safety and how
to not cut the orange wires. These guides are nice technical rundowns on the
vehicles themselves, and well worth reading. Bottom line is that fuel tanks
and airbag squibs are far more hazardous than HV batteries and wiring.
Discussion of THS-II design. [This actually begins a whole sequence]
Discussion of THS-II controls.
Toyota R&D Labs. [english]
Dealers / vendors
Link-nest and various other info presented by Gilles Labelle, a guy who
elegantly balances making auto sales and having genuine passion about
hybrids and clean transportation in general.
Lots of cool accessories for the Prius and other cars. Extensive
lighting section, including interesting LED modules from Japan. CCFL
promised soon, but that's apparently still too new.
Info on the Tamagawa-Seiki position resolvers used in the Prius BLDC motors,
which bring sine and cosine information back into the hybrid ECU. Includes
a little bit about the AU6802N1 "smartcoder" support chip, two of which sit
on the hybrid controller. This product family is aimed at the hybrid
automotive market, and it's quite amusing to see a picture of an Estima
right there on top of their
car applications overview
Mini-scanner site, for the Classic Prius only. Also by graham1.
The CAN-View site, detailing a very cool CANbus monitoring product
that displays on the built-in screen *and* accepts touchscreen
control commands. For '04+ Prius, with and without Nav. A
really nice bit of integration engineering, not to mention
the ability to pull out and display all that "geek info".
A salvage dealer and car-repair outfit specializing in rebuilding crashed
Priuses and/or parting them out. Great source of discounted parts, both
working and nonworking, depending on availability. This guy has done some
completely amazing recovery of hopeless-looking wrecks, and has gotten into
fixing inverters down to the component level, reverse-engineering ECUs,
installing PHEV conversions, you name it.
One of the early Prius pioneers, Dan Kroushl, headed for Autobeyours
for his 180,000 mile maintenance and some other fun fixups, and
wrote it up
with lots of pictures.
Metro Toyota has several add-ons for the Prius, including engine block
heaters [but you have to ask Jesse specifically for those]. Bulk buys of
block heaters often happen via Priuschat -- search the forums.
Carolyn Coquilette's shop, specializing in hybrid diagnostics, repair,
maintenance, and modifications [including PHEV]. A very interesting
and environmentally-conscious approach to automotive servicing, and a
Small format OBDII [now incl. CAN] scan-tool and digital gauge kit designed
to install right on a dashboard. Generic parameters only, although a feature
called XGAUGE to display manufacturer-specific enhanced info is under
development. The newer Scangauge II can also read DTCs and reset the MIL.
One source for buying Toyota parts, from TradeMotion. Uses a very
easy to navigate, browser-friendly tree structure. Human contact info
is sketchy at best, however -- decide your own comfort level.
Sites for a few of many commercial laptop-based OBDII scantools. Some of
these are designed for the professional and claim to include all the
factory-OEM features and parameter-awareness as the "official" tools.
This is still not entirely true, but they're making progress.
More OBDII tools, specifically for CAN.
Another OBDII tool, but with very poor support. Sorry, Alex.
Coastal Electronic Technologies -- various Prius add-on products. Frequent
complaints about poor customer service / response. Some items listed, such
as the engine-run and friction-braking indicator for the gen 3 Prius, have
so far been vapor.
Big Brother data recorders for your OBDII.
BT Tech chassis stiffening plate for the 2rd-gen Prius. Easy bolt-in
upgrade for the stock "U" channel brace, which does much more to
resist longitudinal twisting.
Automotive Tech Training, offering in-depth, hands-on hybrid training classes
for independent auto techs to come up to speed on hybrid principles, repair,
diagnosis, safety, etc. Helping to dispel the myth that all hybrids must go
back to the dealers for service, and leading the way to a time when full or at
least mostly electric propulsion will be the everyday norm in the bays. $$.
Good link-nest to tool companies and other useful auto-tech info.
Craig van Batenburg's instruction center for repair techs. $$$.
Traffic and fuel economy
[Don't let this happen to you!]
The seminal articles on "traffic waves" and how leaving generous
following distance HELPS EVERYONE on the road. The Prius, and the
"damped" styles its drivers tend to learn and adopt for better mileage,
are very compatible with the jam-busting techniques described here.
More articles relating to "pulse-n-glide" and other high-mileage hints.
See the last of these, prius-rally-hints, if you're planning on entering
any sort of mileage competitions in a Prius.
Pointers for getting better mileage from *any* vehicle, not just hybrids.
Basic hints on driving efficiently; a set of articles often referenced by
Edmunds tests and reports on various fuel-saving techniques. From 2005, but
the most poignant conclusion -- "stop driving like a maniac" -- is equally
Autospeed article on Brake Specific Fuel Consumption, one of the major
factors affecting efficient combustion-engine operation.
Power generally required to overcome air resistance at different
European campaign to promote "ecodriving", or better techniques for improving
MPG and safety with driving style. Training efforts are already underway in
the Netherlands and spreading across several other countries.
Visual guide to evaluating distance and time in tailgating offenses, useful
for reporting unsafe conditions based on quick pictures snapped on the road.
Fight back against highway terrorism, even if it means that some people
need to explore different careers!
Great rant on why "nanny cars" with overly-mollycoddling safety and
convenience features are killing us by creating more bad drivers.
Sensible rules for road safety. If demonstrated knowledge of these things
were *required* to obtain and hold a driver's license, we would all be
so much farther ahead -- but likely with far fewer people licensed to be
on the road.
A proposed "state of the union address" segment introducing the idea
of a country-wide campaign to universally endorse and enforce safe
vehicle following distances of three seconds or more. Unlikely to ever
go out over national TV, but it's nice to dream sometimes.
Promo site for the "Traffic Safety" book by Leonard Evans. He has many
interesting ideas, such as distributing traffic penalty monies back to all
drivers, and other proposals to encourage safer *behavior* on a wide scale.
The "Yuppie Button", a defensive way to use rear-firing lights to help
maintain safe space on both ends of the car. Some hardware/wiring
modification required. Turns out that it's a prototype of enhanced
stop-lighting ideas now under consideration at the NHTSA.
More evidence on the dangers of cellphones and other distractions while
driving. Put that thing down and PAY ATTENTION!
Funny article on the stereotypical "Boston driver" or "Masshole".
ABC News interviews Wayne Mitchell about hypermiling techniques. Wayne is
the "block heater guy", who has traveled all over the country installing
engine-block heaters for many other owners just because it's a good thing
to use for increasing overall MPG -- even in warm weather. It still puts
energy into the system, from the wall rather than from burning fuel.
High-efficiency driving advice from a Ford engineer. Has links to some
related articles near the end.
Buick vs. Kenworth == six feet under: what happens when a car driver fails
to notice an oncoming semi-truck and pulls out in front of it. Shot by
"300kmileprius" at CleanMPG,
who sent it along to be hosted here and relates: "Location was Salem, Indiana;
late June 2006. Nearly forty people had gathered around by the time I
happened to arrive. I just walked up to the front of the crowd, snapped
a couple of pictures, and walked away."
Analysis of driving psychology and road-rage. This site is full of
excellent related articles. What are YOU thinking behind the wheel?
Getting a little extreme with the safety/conspicuity enhancements on a
Prius, as part of ongoing efforts to maintain safe spacing and visibility
in traffic especially at night. Simple but effective use of industrial
EcoDriving USA, an arm of the Auto Alliance in Washington DC, offering
various educational material and advocacy on ecodriving. Warning:
information. They have a fairly complete
PDF manual on the subject available for download, albeit the advice
within is pretty much the same generic stuff found everywhere else --
directly linked here because finding it over there is challenging at best.
One viewpoint on what hypermiling/ecodriving is all about, sort of
in response to the bad publicity gaffe that the AAA public-relations
people came up with about the "dangerous hypermilers" on the road.
Far from it!
Resources advocating increased installation and use of roundabouts /
rotaries, proper design and usage of which have proven congestion-reducing
effects. Roundabouts are also great for the hypermiler, allowing much
more accurate planning as opposed to trying to second-guess a signal.
The other articles/papers at
aaafoundation.org are also quite interesting and relevant.
Federal Highway Administration info on roundabouts/rotaries. A largish
PDF, but well worth reading.
Mike Spack, a traffic engineer, discusses roundabouts.
Miscellaneous articles on roundabouts, "naked intersections", and surprising
insights about the rules of urban travel.
Tom Vanderbilt, author of "Traffic" and the
howwedrive site, discourses
on the benefits of roundabouts.
More from Tom Vanderbilt, reflecting on the discoveries and achievements
of Hans Monderman, another European traffic engineer who helped spearhead
the "naked intersections" idea. Long, but well worth the read and contains
some great quotes like
The masters of space and time awaken to find themselves slaves of distance
(Wolfgang Sachs, For Love of the Automobile, 1992)
The "diverging diamond" interchange, which allows greater routing
efficiency and easier "left turns" in a smaller paved footprint. Takes
a little getting used to by drivers, who wind up proceeding on the left
side of the road for a little bit.
Thoughts on why our underlying animal instincts may have trouble seeing
electric vehicles as sufficiently "sexy".
Tony Scotti, a security and defensive driving instructor, writes on executive
protection, ambush avoidance, and other evasive and performance driving
techniques. Not really about normal everyday commuting, but anything that
endorses 100% attention to the task of handling a vehicle is a good read.
MPG experiments with a Jeep Wrangler, along with a good general discussion of
OBD II, factors affecting MPG [or not], and an extensive link-farm at the end.
Review/comparison of two GPS units from the same company, clearly revealing
the decline and fall of Garmin. In terms of UI design and not insulting
a buyer's intelligence, they're done.
Project sites and other fun pages
One of the first groups working on plug-rechargeable battery mods to the
Prius, which they're calling Prius+. Very vocal and high-profile about their
work, and recently announced the EnergyCS pluggable-Prius modification,
expected to go fully commercial soon. See also edrivesystems.com,
hymotion.com, pluginsupply.com, and the "priusplus" yahoogroup.
Mike Dabrowski's extensive resource about the Honda Insight, his MIMA
modifications, electric cars, tech training, and many other hybrid and
alt-fuel projects and inventions. He is the true guru of the Honda
Insight, which is still the fuel-economy leader after all this time.
[*Note: there are many references to "techno-fandom.org/~hobbit"
from here down -- a justifiable bias, since they document all *my* hacks.]
An amusingly simple wiring hack to enable the power windows in a Prius
without turning on the rest of the car. Also contains some details on
safely removing the dashboard vents and panels without breaking them.
Details on building an analog battery current meter to read flow into
and out of the hybrid pack. Uses the stock Toyota hall-effect sensor.
Details of L. David Roper's Hymotion conversion process and observations.
A very simple "engine is running and consuming fuel" indicator, described by
a very silly webpage. This has since been merged into an instrument panel.
To squirt or not to squirt, that is the question. Here's the answer to
the latter; a very simple fuel-cut switch that also allows playing around
with various engine-failure conditions. Also has some discussion of the
"high-speed EV" modes being offered by various PHEV providers, and why
they might not be such a hot idea after all.
How to install an aftermarket tachometer into a Prius, including notes
on how tachometers work, how to test and calibrate them, and how to hack
an older one to be compatible with the car's signal levels if necessary.
A modification to the regenerative braking system on the Classic Prius,
to make greater use of regeneration and less of the brakes.
Working prototype for a hydraulic-brake-pressure monitor, that helps
determine when you're no longer regenerating.
An experimental hack to redirect engine air intake from a warm air source
rather than a cold one, with the intent of increased winter economy. Some
controlled-test results are posted underneath. See also: "heatgames" ...
Winter preparation: an improved version of the above warm-air intake,
plus a detailed account of removing the cowl above the engine and
installing a block-heater from above. If you're thinking that the
big piece that the wipers fit onto is scary, it isn't! These pages
make cowl removal easy.
A circuit to read the raw output voltage from the engine coolant
temperature thermistor, and convert it through a "linearizer" to a
reasonably close mapping from degrees C to volts.
A strange but functional tire-pressure warning system, based on wheel
rotation speed differences. Provides a rather entertaining display.
A simple and robust way to mount a GPS power cradle using the vent-panel
as a base, which puts it in a good position for both driver visibility
and receiving a wide sky's worth of satellite data.
Installing cruise control, hybrid gatherings, and other stuff.
One of several efforts to use the Prius as a home generator / UPS.
Another UPS / generator project, with up to 1 KW capability [but that
does draw a *lot* of current from the 12V system].
Yet another method of tying in a UPS. The 450VA Best Ferrups has 66 Ah at
12V inside, way more than the Prius battery itself. The right answer,
however, is to stop messing around with this feeble 12V nonsense and
build a 10kW or more inverter that feeds directly off the HV battery.
Crocking together a collection of parts to charge a spare Prius hybrid
pack and run a UPS from it, during some slack time at Tour de Sol. It
made a great albeit slightly dangerous demo.
Mac Mini integration to onboard display screen.
Mostly-Japanese sites; pointers to several other Japanese-only sites.
Worth a look even if you don't read Japanese; the project pix tell
quite a bit about what people there are hacking on. The latter site
is where "Ken@Japan" details his SuperMID instrumentation projects.
Robin Mitchell looks at how much 12 volt power is needed to boot a Prius.
Conclusion: jump boxes or booster batteries need to be able to supply ~ 30A
without sagging. It would be interesting to repeat the experiment with
the DC/DC output disconnected and see more of the running steady-state!
A hilarious and very down-to-earth look at electric vehicles and surrounding
environmental issues from a woman's standpoint. Lots of good links to
other resources about electrics, batteries, hybrids, and alt-fuels.
More Prius links and discussion from the point of view of an Insight owner.
Documents easter-egg dances for user-settable things such as reverse beep.
Check out the rest of
eaa-phev.org too, it's quite interesting as another plug-in
Prius mod clearinghouse, and getting more extensive all the time.
Simple guide to removing the lamps in the door "courtesy" lights in order to
avoid excess 12V battery drain. Includes a means of amply compensating for
the safety aspect of disabling the lights with "reflective bling".
Darelldd's extensive Prius mods/hints/fun pages, from the perspective of a
guy who's been driving solar-charged EVs for several years and is really
into LED lamp replacements and many other energy-saving projects. Darell
is also quite active on Priuschat.
Four new Michelin "Green-X" Energy Saver tires installed on the Prius
in late 2009, using metal bolt-in valve stems instead of rubber and taking
the opportunity to document the whole process.
A PHEV conversion in the UK, whose builder Nikki has valiantly pressed on
despite at least one hopelessly overcharged pack and is definitely still
in there doing it ...
Some silly "photochopper's concept" ideas (ahem) on how to paint up
the plastic trim rings for different effects. Frankly, it seems like
simply pulling them off is the best approach.
Funny Prius pseudo-ads by David Krulik, involving hookers and dead bodies.
Adventures in "debadging" a Prius, and minor bodywork/painting artistry to
de-emphasize the blank areas left behind.
Another personal collection of hacks to a 2002 Prius.
Collages of three years' worth of "slideshow" -- reflecting all the fun
to be had with hybrid vehicles, their tech, and the community around them.
Interesting DIY EFI stuff.
Home-made OBDII interface info.
Jeremy Clarkson, normally a rather gear-head auto writer who is actually
rather disparaging about hybrids, has a hilarious take on motorcycles
Links and support for "MegaSquirt", a complete, open-source EFI system
that you can build, calibrate, and tweak yourself. Unrelated to the Prius
specifically, but great reading for learning about fuel-injection systems
One person's EV conversion chronicle.
This is only a tiny sample of the Controller Area Network and other data
network info that's floating around out there. Attila Vass, in particular,
has some good info about pulling realtime data off the CANbus in the '04 and
up Prius; the equivalent of the miniscanner for the "classic" is a likely
result. The "Prius_Miniscanner_MarkIII" yahoo-group also exists but
doesn't have public archives.
Attila's CAN project.
can232 / serial converter dongle[s] ; USB soon.
Low-level CAN protocol documentation from Kvaser.
Their (outdated) copy of the original BOSCH spec can be directly
Other files in their download area hide behind a similar syntax if
you don't want to deal with their silly intrusive request form.
The original CAN protocol and other documentation from Bosch.
Using a simple switch box to isolate a separate chunk of CANbus from
the car so that scantool requests can be analyzed, to a degree.
Has details on how OBD-II protocol is encapsulated inside CAN and
some of the specifics on collecting data from the ECUs in a Prius.
Uses the manufacturer-specific data item for fuel injector time as an
example, and why that is a particularly good parameter to monitor.
A companion file
sgpkt.txt breaks out the CAN packet protocol and the encapsulated
ISO15765-2 queries/responses inside.
CAN in Automation news and standards/specifications site.
CAN chipsets and stuff.
AVC LAN and other car-audio stuff from Fujitsu Ten.
Various U.S. patents relating to the Prius, filed by Toyota to
mirror the Japanese patents. If freepatentsonline is unreachable,
check uspto.gov. Basically, any time Toyota says "power output
apparatus and method of controlling the same", they're talking
about hybrid drivetrains.
Effectively the "master" Prius driveline patent. Covers all possible
operational modes and control of the engine-plus-two-motors system.
Battery charging control.
Canceling battery "memory effect" via infrequent wider charge/discharge
Regenerative drivetrain torque control, including engine jake-braking mode.
Electronically-controlled braking system.
Braking control in general.
Regenerative/electronic braking fail-safe mechanisms.
Engine start/stop via the two motors and power split device.
A few non-Toyota patents that are nonetheless interesting from an
Hydraulic energy storage for hybrid vehicles [concept].
Can't find something? Google is your friend, even if they do keep
big-brotherly details on what you surf.
[Reading the HTML source may turn up a couple of other surprises, too.]