Converting a Yaris into a plug-in hybrid

Toyota may have something up its sleeve 27

The first car I ever owned didn't have power anything. Today you will be hard pressed to find a car without power brakes and steering. But those features also consume energy. This explains how the first wave of economy cars from Japan got such notoriously high mileage (they didn't have power anything either).

One reason I chose a Yaris for my next car is that it has electric power steering and power brakes. In theory, you should be able to turn the engine off without losing power boost. I asked a mechanic at the dealership before I bought the Yaris if the power steering and brakes would continue to function with the engine turned off. "No, no," he said definitively. "It's just like any other car."

Surprise! The mechanic didn't know what he was talking about. I've turned the Yaris engine off several times now while going downhill and the power boost systems continue to function just fine. Don't try this at home.

[update] Seriously, don't try this at home. The mechanic was partially right. I've discovered that, given enough time, the brake boost system will eventually depressurize leaving you with insufficient braking at the bottom of a long hill. The Toyota engineers left power boost running just long enough to get you out of a pickle in the event of inadvertent engine shutdown.

I found it hard to believe that Toyota engineers would turn off the electric motors that could run on battery power just because the engine died. It would be a no-brainer to keep the power brakes and steering alive for safety reasons.

I'll be able to turn it off by pushing a button and start it again by pushing another without losing power steering and brakes. Turning an engine off does not always save gas. It takes extra gas to start an engine and extra energy to charge the battery back up after it is used to turn the starter. A general rule of thumb is that you will come out ahead if your engine is off for 30 or more seconds. I'm going to experiment with this switch setup to see what it does to my mileage. I sometimes haul a carpool of kids to a school at the top of Capitol Hill across town. Coming home is downhill all the way. I should be able to keep the engine off for much of the trip.

I should also be able to recoup some of the energy lost charging the battery. When I put the car in neutral, the engine rpm increases noticeably. This means that the Yaris automatic transmission is drawing significant power from an idling engine when stopped at a light. I might as well capture some of this in the battery, which will be used pretty hard, by putting the car in neutral as often as possible when the engine is idling. There is a chance that I can drain and therefore ruin the battery by using it to power the boost system.

All cars already have a heavy electric motor that they haul around for occasional use. It's called a starter. Some pseudo-hybrid car designs are already automatically turning the engine off at stops to increase gas mileage and have modified the starter motor and increased the size of the battery to get the car rolling and to restart the engine. They also use some regenerative braking to keep the battery topped off.

I have a similar goal, except I intend to bring along some grid-charged batteries. All I need is enough electrical power to get the car rolling from a dead stop in stop-and-go traffic, or to keep it rolling on level ground at low speeds. It would not be used to shove me up big hills or exceed 30 mph. I have no illusions of using the Yaris starter motor for this. I'm thinking along the lines of modifying a small trailer that can nudge the car along on short in-city trips and be unhitched for other trips. Why haul a motor and batteries around when you don't need them?

The Yaris appears to have a sophisticated starter solenoid already in place. Close the circuit to it for a fraction of a second and it takes over, starting the engine for you. Old starter solenoids required the driver to keep the switch closed until they determined that the engine wouldn't die. These discoveries make me suspect that Toyota is contemplating a hybrid version of this car.

Certainly, the Prius somehow knows when to start and then starts its engine. I'm not sure cars should be that smart. Call me paranoid, but I suspect they may be self-aware. I also don't like the way they stare at me.

My real name is Russ Finley. I live in Seattle, married with children. Suffice it to say that although I am trained and educated as an engineer, my passion is nature. I very much want my grandchildren to live on a planet where lions, tigers, and bears have not joined the long and growing list of creatures that used to be. In an attempt to minimize the workload on Grist editors responsible for turning my submissions into intelligible articles, I will also be posting on a seperate blog called Biodiversivist, which will contain articles in addition to those submitted to Grist.

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  1. Sean Casten's avatar

    Sean Casten Posted 4:48 am
    12 Jun 2008

    One of my favorite presentations on HEVsWas given at a conference about 10 years ago by Delphi.  Wish I still had it but it was at the end of a day full of presentations from a lot of HEV/EV/FCEV wonks, all of us joyfully talking about how great these would be from an environmental perspective and how big the engineering challenges would be, etc.
    The Delphi guy stood up and said "all cars will be HEVs by 20XX (I forget the year).  all cars will be EVs by 20XX.  And it has nothing to do with anything anyone here is talking about."
    He then put a slide up showing the average on-board electric load for all vehicles sold in the US, starting with Henry Ford and going to the present.  It started at zero (in the days of handcrank starters and acetylene headlamps) and gradually ramped over the ensuring century with a fairly steady slope.  He then layered on the various demands for on-board electricity that had driven those increases through the years.  Headlamps.  Radios.  Air Conditioning.  Power Steering.  Then he layered on top of that the ways that autos had evolved to serve those loads: Batteries.  Higher voltage batteries.  Alternators.  Starter/alternators.  Finally, he layered on the things that the marketing department was saying had to be in next-generation cars: GPS.  Heated rear seats.  Satellite Radio.  
    You get the point.  The interesting thing was that he then layered on the technical limits of our current electric technologies on cars and showed that we were about 5 - 10 years away from hitting the limits of on-board electric power supplies, assuming that trend continued.  And by extrapolation, you could then see the point at which HEVs and EVs became inevitable.  
    All very interesting.  And maybe that's what Toyota's really up to...
  2. hapa's avatar

    hapa Posted 5:07 am
    12 Jun 2008

    the autoblogs are all a-twitterwith a "prius" brand of cars. the "hybrid synergy drive" moniker was a failure, time for "the lexus of green." in the line-up seems like the smaller one and maybe also -- finally, hello -- a wagon or microvan SUV killer.
    but it's too late. the market for "premium" new cars will keep shrinking this year and maybe next year as the "bullish" oil prices wipe out the people on the brink from the credit crash.
    i think the family car will need to be something more like UCS's "vanguard" vehicle. off-the-shelf, cheap, light, normally aspirated. something people can afford.
    in the meantime the auto industry needs to stop building proprietary electric powerplants and batteries. modularity and a much larger coordinated research, development, deployment, and subcontracting program is the only way to get costs for electric down where people need them to be in a short time.
    particularly important is building cars around a physical battery standard -- a market -- no more fighting for contracts by form factor. build a better battery in the standard size and someone big will snap it up for some of their run of some vehicle. buyers may even select cars by the brand of battery, tune the battery system, etc.
    in the short term though opening it up will get it out the door faster and cheaper.
  3. amazingdrx Posted 4:32 pm
    12 Jun 2008

    A different pluginThis is interesting bio-d, use only a couple of extra plugin bateries (cheap heavy ones would be ok) to boost your mileage maybe 20 mpg?  By only having the extra plugin batteries power the electric part of the car, including restart (that eliminates the 30 second payback rule) and move it at low speed without restart.
    Why use gasoline to recharge the starting battery or power any accesories?  use grid power in the extra batteries.  Put the alternator on the "off" position even when your engine is running too, because the extra batteries would tell the charge circuit the battery doesn't need charging, no switches needed.
    Depending on how much time one spends stuck in traffic creeping at under 10 mph, this could get you 20 more miles per gallon.  A compression release for the gas engine would be good too (not sure how difficult that would be), and maybe an electric oil pump to maintain oil bearing pressure in the engine when you creep forward at low speed on electric power through the starter.
    Also realize that much more powerful 24 volt starters are available after market.  They are used to crank high compression hot rodded engines.  Some sort of cooling for the starter might be good, fan forced or liquid heat pipe. That'as a pumpless liquid cooling system, it pumps the fluid with the waste heat to a radiator.
    You won't need a trailer this way.  If you could get even 20 mpg more with a few extra batteries, an electric oil pump, and an aftermarket starter added to your engine switch, that would be a coup!
    Go for the easy cheap, low hanging plugin fruit, so to speak.  Sure plugins will go 60 miles at full speed on a charge someday, but the batteries to do it are held closely by corporations now and far too expensive.
    Great sequel to your bike.  We're right behind you, go for it!

    http://amazngdrx.blogharbor.com/blog
  4. amazingdrx Posted 6:07 pm
    12 Jun 2008

    30%If 30% of the trip was either at below 10 mph or downhill, allowing the starter power alone either to creep along in traffic (all accesories powered by plugin) or to nudge the car to the right speed, mileage could go up from 35 mpg to 55?  Does this make sense?
    Upgrading batteries as they become available and affordable, and installing a higher voltage, higher power starter would eventually up the top plugin speed and mileage.  This design could get over 100 mpg eventually, in slower city traffic commuting especially.
    A kit would be pretty easy to install, the firefly Oasis batteries might be right for this.  Also carbon fiber replacement parts for the car, aftermarket available (?) would lighten the car to make up for battery weight.
    A great hobby.

    http://amazngdrx.blogharbor.com/blog
  5. Biodiversivist's avatar

    Biodiversivist Posted 12:34 am
    13 Jun 2008

    We are thinking along the same lines DrXThere's a weight penalty for a system that will only be used for in-city driving. You can't be lugging a few hundred pounds of dead weight around when on the highway. This system would have to be light, using lithium batteries and higher voltages. It would be good for nudging you along in stop and go traffic, to get you rolling down a hill, accelerating out of stops and keeping you moving for short distances on level roads.
    If people get lazy and stop bothering to plug-in their hybrids, they will incur a mileage penalty from the extra weight as well. Ideally, the goal is to use everything you got all of the time.
    I don't want to use the Yaris starter because I will probably tear teeth off the flywheel or burn out the motor. Neither is designed to move a car from a dead start. In addition, the starter would have to turn the engine as well as the wheels. I'll have to be careful not to hit the starter button while in drive because the button bypasses the transmission lock-out.
    Here's a company that is converting cars using lithium batteries. They don't look like A123 cells. Note that's a Yaris they're driving. Maybe they should consider a simple hybrid system just for in city driving, that way I wouldn't have to build my own ; )
    http://www.voanews.com/mediaassets/english/2008_06/Video/ ...

    In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
  6. amazingdrx Posted 2:21 am
    13 Jun 2008

    YepI can see why you don't want to use the standard starter and flywheel and wreck them.  Or drive the engine with the starter when cruising on plugin power.
    An extra electric motor on the transmission side of the clutch/flywheel assembley would be complicated.  I still like the idea of a parallel plugin drive on the back wheels.  Even one back wheel powered for low speed would be ok.
    But the notion of powering all the electrical load in the car with plugin would be cheap and possible. I wonder how much fuel would it save?
    Could a heavier starter motor handle traffic creep speeds without damaging the flywheel?  It's possible.  Toyota makes better parts that mesh better than the old flywheel/starter combination us do-it-yourselfers are used to from fixing big three planned obsolesent engineering.
    Especially post 60s Fords, new Ford trucks from the past few years are rumored to take multiple transmission replacements in normal service, over only the first few years!  My F-250 would start and run in gear with the clutch inoperable without harming the starter or flywheel, that was a different time in the US auto industry.
    The thing is that a "faux" hybrid with starter electric power could  get real hybrid mileage gains with extra plugin batteries powering all the electrics.   It would be a cheap way to convert to plugin.
    A Prius conversion or full lithium electric (as featured in the video) will continue to be very expensive due to battery scarcity.  Until mass production takes hold, if ever?

    http://amazngdrx.blogharbor.com/blog
  7. jcwinnie Posted 4:16 am
    13 Jun 2008

    PluginThe reward for schlepping batteries around all the time comes from having a kinetic energy reclamation system.
  8. amazingdrx Posted 4:38 am
    13 Jun 2008

    Can't agreeThe advantage from plugins is mainly from substituting electricity for gasoline.  Regenerative breaking is not necessary to drastically cut GHG, especially if renewable power, such as solar PV on your roof is used to charge.
    Lugging batteries is worthwhile to reclaim breaking energy, but not worth the trouble for an economy conversion to plugin hybrid.  The plugin feature saves many times the GHG.

    http://amazngdrx.blogharbor.com/blog
  9. Green Guide for Maui Posted 7:49 am
    13 Jun 2008

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  10. amazingdrx Posted 3:00 pm
    13 Jun 2008

    Great blog!http://www.greenmauiguide.com/index.php?option=com_conten ...
    Very thoughtfull comments, excellent.  I'll check the electric car stuff.

    http://amazngdrx.blogharbor.com/blog
  11. John Fish Kurmann Posted 8:29 am
    14 Jun 2008

    Fuel-saving features on Japanese versionHi, biod. A possible explanation for some of the interesting features you've found in your Yaris that have left you wondering if they're planning a hybrid version may be that the Japanese version--called the Vitz--comes with Toyota's Intelligent Idling Stop System (IISS), which shuts the engine off when idling at stoplights/signs and in traffic. This is one of the features that was deleted from the U.S. version to lower its cost because most Americans (at least until recently) only bought subcompact cars because that was all they could afford. The Vitz also comes with a continuously-variable transmission, which improves fuel efficiency, as does electric power steering. In Japan, of course, a small car isn't necessarily a stripped-down, no-frills budget car. I think it's a shame Toyota doesn't offer a top-of-the-line Yaris in the U.S. with IISS and a CVT in addition to offering base, no-frills versions. I haven't been able to determine whether any European versions of the Yaris offer the IISS, though the U.K. version does have more other amenities than the U.S. version.

    "You can never get enough of what you do not really want." - Huston Smith
  12. Biodiversivist's avatar

    Biodiversivist Posted 12:13 pm
    14 Jun 2008

    Very interesting, JohnThanks for that link.

    In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
  13. Biodiversivist's avatar

    Biodiversivist Posted 12:28 pm
    14 Jun 2008

    PSI just drove it from 65th and Ravenna to 36th and Stoneway in Seattle with the engine turned off almost a third of the distance. In theory, I just increased gas mileage maybe 30%, approaching 45 mpg city for that leg. Unfortunately, it may take me half of the summer to use a tank of gas so getting mileage calcs is going to be slow.
    Another good point John, is that small cars in other countries can have a measure of prestige via accessories instead of size. I've noticed that the wealthier drivers of Priuses flaunt their GPS, rear cameras, and keyless entry over those without them--none of which affect gas mileage.

    In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
  14. hapa's avatar

    hapa Posted 1:37 pm
    14 Jun 2008

    the japanese prius 2parked itself. when they sent the car to europe they sold self-parking as an option and it was very popular. here i think toyota offered it on a lexus, first. probably thought people would say a small car that could do fancy tricks was for stuck up sissies.
  15. John Fish Kurmann Posted 2:52 pm
    14 Jun 2008

    I should've noted......that the continuously-variable transmission (CVT) available in the Japanese Vitz improves fuel economy over an automatic transmission (AT), though the driver operates both in essentially the same way; that is, you don't have to shift gears manually with a CVT or automatic. I think a vehicle equipped with a manual transmission (MT) will typically still achieve a bit higher MPGs than one with a CVT, though that's not always the case. Even without a CVT, though, Toyota managed to nearly match the MPG rating of the MT-equipped Yaris with the 4-speed AT-equipped Yaris.
    Nissan has been the most aggressive automaker in switching from ATs to CVTs to improve fuel economy.

    "You can never get enough of what you do not really want." - Huston Smith
  16. John Fish Kurmann Posted 2:54 pm
    14 Jun 2008

    I should've noted......that the continuously-variable transmission (CVT) available in the Japanese Vitz improves fuel economy over an automatic transmission (AT), though the driver operates both in essentially the same way; that is, you don't have to shift gears manually with a CVT or AT. I think a vehicle equipped with a manual transmission (MT) will typically still achieve a bit higher MPGs than one with a CVT, though that's not always the case (the Nissan Sentra is one contradictory example). Even without a CVT, though, Toyota managed to nearly match the MPG rating of the MT-equipped Yaris with the 4-speed AT-equipped Yaris.
    Nissan has been the most aggressive automaker in switching from ATs to CVTs to improve fuel economy.

    "You can never get enough of what you do not really want." - Huston Smith
  17. amazingdrx Posted 3:09 pm
    14 Jun 2008

    CoastingGreat mileage increase from coasting.  I am still wondering how much it would increase by substituting plugin power for the entire vehicle electrical load.
    It might allow another 5 mpg?  

    http://amazngdrx.blogharbor.com/blog
  18. Biodiversivist's avatar

    Biodiversivist Posted 2:00 am
    15 Jun 2008

    Don't know DrXWould have to test the idea.
    I liked manual transmissions until moving to Seattle. Sitting nose up on a steep hill with a line of cars behind you inches away from one another's bumpers is a real pain, requiring fancy footwork and a parking brake within arm's reach ...that works.

    In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
  19. amazingdrx Posted 2:32 am
    15 Jun 2008

    How much?How much energy in terms of percentage of total engine output does the electrical load consume?  Not sure if those figures are available bio-d.
    How much does air conditioning consume?  I suppose it depends on local climate, weather, and traffic jams.
    Idling in traffic for half the time of the commute in southwestern heat, for instance.  That amount of wasted gas (maybe half the trip's worth?) would surely be worth replacing with plugin battery power.  The air conditioning would need an electric motor of course.
    Commuting in the northwest without traffic jams wouldn't save as much gas.

    http://amazngdrx.blogharbor.com/blog
  20. Nucbuddy Posted 2:45 am
    15 Jun 2008

    'Getting mileage calcs is going to be slow'Biodiversivist wrote: it may take me half of the summer to use a tank of gas so getting mileage calcs is going to be slow.
    Indeed, it seems that you are not putting this vehicle-capital to work. If you are already using very-little fuel, what is the purpose of this project? Earlier in this thread, you wrote, "Ideally, the goal is to use everything you got all of the time."
    Commercial and fleet vehicles do that. Private vehicles do not. Again, what is the purpose of this Yaris-conversion project? So that objective evaluations can be made, would you please post your money- and/or fuel- saving goals?




    In the Original Post for this thread, you wrote, "I sometimes haul a carpool of kids to a school at the top of Capitol Hill across town. Coming home is downhill all the way."
    It sounds like you are deadheading on the way back. Have you considered hiring a taxi for this job, instead of doing it yourself? Taxies rarely deadhead.

  21. amazingdrx Posted 2:59 am
    15 Jun 2008

    HmmmThis brings up an obvious question.  Are there any mileage meters that retrofit on a vehicle available?  Measuring fuel consumption and comparing it to distance traveled on a cumulative basis?
    Available at an affordable price?  This would seem to be a good after market product area to exploit.
    And drive-it-yourself credit card low-speed electric plugin taxis?  the card machine on the vehicle, connected wirelessly.  Good idea buddy, thanks. Golf cart type plugin vehicles are being legalized for limited road use everywhere people retire!   Hehey.
    This is a vehicle ready made for transportation coops.  Local non-governmental socialism rules!  Power to the people.

    http://amazngdrx.blogharbor.com/blog
  22. spaceshaper's avatar

    spaceshaper Posted 3:08 am
    15 Jun 2008

    FRORINucbuddy makes a valid point in that, in general, those who drive little generally create a very small benefit either for themselves or the environment when they invest in a high-mpg vehicle: the Functional Return On Resources Invested, from either perspective, is likely to be quite low and opportunity cost considerations have to come into play.
    On the other hand, BioD is an engineer and a tinkerer, both honorable avocations, and I believe we can expect something particularly valuable to come out of this exploration. BioD, we wait with bated breath!

    The true meaning of life is to plant trees, under whose shade you do not expect to sit.
  23. Biodiversivist's avatar

    Biodiversivist Posted 3:57 am
    15 Jun 2008

    Father's day gifthttp://www.scangauge.com/

    In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
  24. Nucbuddy Posted 5:28 am
    15 Jun 2008

    Engineering the socially-relevantSpaceshaper wrote: those who drive little generally create a very small benefit either for themselves or the environment when they invest in a high-mpg vehicle
    Therefore, Biodiversivist's Yaris-conversion project has no relevance to Gristmill.




    Spaceshaper wrote: On the other hand, BioD is an engineer and a tinkerer
    Do you think it might be possible to engineer and tinker-with things that are socially-relevant?

  25. BILL HANNAHAN Posted 7:39 am
    15 Jun 2008

    What is the standard?
    If somebody built a coal fired car would it be fair to say that it gets infinite miles per gallon, or should total emissions of all harmful materials be the standard?

  26. spaceshaper's avatar

    spaceshaper Posted 10:30 am
    15 Jun 2008

    to Nucbuddy:I endorse your earlier point that anyone who drives as little as Biod's post suggests should consider not buying a car at all. However Biod's purpose with his particular purchase goes beyond that of its use as a personal vehicle and though his is a small-scale project it could possibly have benefits for us all. The investment - of time, expertise and money - is his own. He has been most generous with sharing his electric bike development experience and I believe we can expect more of the same from the current project. I suggest it is your mean-spirited commentary, not Biod's project, that deserves no place on Gristmill.
    to Bill H:
    Huh?

    The true meaning of life is to plant trees, under whose shade you do not expect to sit.
  27. amazingdrx Posted 2:22 pm
    15 Jun 2008

    DisgruntledMy guess is the recent bad nuclear financial outlook has him feeling a bit grumpy.
    Nuclear power has been dropped like a bad transmission.

    http://amazngdrx.blogharbor.com/blog

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