000: The leadup
It all started around February 2005 with a renewed interest in finding out
what types of hybrid cars were becoming available. My conventional wagon
wasn't that old but was becoming rather tiresome, in need of basic maintenance
that the depths of a long winter necessarily pushed off, and with a relatively
insatiable thirst for fuel even at 25 mpg or so. I realized that anything
larger and more van/SUV-like would probably see even less mileage, so while
the wagon was okay as a sort of interim solution there *had* to be something
better coming. Hybrids to date seemed like cute toys, but not really ready
for prime time yet and only as tiny little commuter cars. But there were
things like hybrid buses already on the roads, mostly in other countries
that were much more sensible about fuel consumption. So how about a hybrid
minivan, as a small but efficient freight-hauler for the rest of us?
A couple of simple google queries later, I was deep into a research project
that would occupy most of that February. There *were* hybrid minivans being
sold, dammit, but only over in Japan as something called the Estima. I even
found pictures of it kicking around. Something with a small-to-midsize
minivan form factor and much higher mileage could be the perfect work-truck.
But the blood-for-oil cartel was clearly causing Toyota to not sell them in
this country. The potential market for such things could be *huge* -- soccer
moms, couriers and delivery fleets, local contractors who could take a base
model and rip out the back to install tool shelving ... all bopping around
town through their daily routines and burning a lot less gas. Could I
possibly be the only person thinking along these lines? Hardly.
My continued chasing of ratholes kept turning up tons of information, about
the Prius and other hybrids as well. With that research finally came an
understanding of how the Prius drivetrain works -- much of that thanks to
Graham Davies and his very cool animations [see the link-farm for pointers],
and the archives of several Prius forums and Yahoogroups. I was very amused
to learn that its motor/generators are 3-phase permanent magnet, under computer
control via racks of power transistor half-bridges in the inverter box.
Finally, something efficient and fairly simple. No field current, no slip
rings, none of that "alternator legacy" -- because magnets themselves have
gotten much more powerful and durable and it really is the right way to do
regeneration. Not only are reversing and regeneration dealt with quite
elegantly, the motor windings themselves can be switched as boost inductors
to kick up a much higher voltage. Yow. They've made useful regen braking
work down as far as 7 mph. And the rationale behind the "parallel hybrid"
began to make a lot more sense, as unusual as that makes the drivetrain, once
I realized that the major components could be downsized from where they'd
need to be in a "series hybrid" and thus gain even *more* efficiency.
Soon enough I found a bunch of the Prius-modder sites as well, which are
fascinating from a home-hack-reverse-engineering standpoint since Toyota is
consistently tight-lipped about specific inner workings of their hybrid
systems. But already it was clear to me that the Prius contains some really
good engineering, and that some amount of documentation on it [i.e. the
service manual] could be obtained. And the related patents, freely available
online, pretty much set forth the whole design basis. I sat there pulling
down and reading EVERYTHING I could find -- even staring closely at pictures
from the Japanese Prius-hacking sites, even if I couldn't understand the text
that went with them. I naturally gravitated toward the more technically-
oriented groups and began devouring their collective knowledge-bases and
So the only near-term possibility for largish capacity seemed to be Toyota's
Highlander, which was *about* to come out in a hybrid model. The Prius was
clearly just a sedan and would never do for my occasional gear-hauling needs!
And the Honda offerings, even smaller than that, were already Right Out, and
I didn't quite agree with the way they implement their electric-assist hybrid
in the first place. Anything resembling a minivan wasn't even on the horizon
yet, at least in the US. A Highlander would still bear that SUV stigma, but
maybe not so badly if its hybrid variant could achieve way better mileage.
There was almost no information out about the it except that it was way
overpowered, and likely to be expensive. The sketchy literature promised
a larger version of the same type of drivetrain as the Prius, with an
additional traction motor in the rear, but that was about all I could find.
There was also a little info about Ford's hybrid Escape offering floating
around, but what people were mostly saying about it was that Ford actually
licensed Toyota's drive system technology and then screwed it up somehow and
were having many problems in the field already. Leave it to the American
market to take something reasonably good and turn it into shit -- Microsoft
being the highest-profile example over recent years.
So I wandered in to a local Toyota dealer and went and measured the back of
a non-hybrid Highlander, just to get an idea of its capacity. It was a
bit smaller than I expected, in fact, and the wheel wells protruded into the
rear space in a rather odd way. And the dealers kept going on about its "270
combined horsepower!", which is the last thing on my mind when considering
vehicles. Still, it was a little taller than the wagon I had already and
looked somewhat promising because of that, so I went ahead and signed up on
that dealer's Highlander wait-list and went back to studying Prius stuff.
I figured that better general knowlege of Toyota's "Hybrid Synergy Drive"
and related systems would come from reading about the Prius anyway.
As I wrote to my parents around that time...
Something has also stirred in me a strong desire to learn more about
hybrid cars and motor-controller innards and what all the fuss is
about concerning Priuses. Well, I finally understand how that wacky
drivetrain of theirs works -- the planetary gear diagram that Dad and
I were staring at for a while. It's really quite cute, and has high
geek value from a design standpoint. The three major components --
engine, large electric motor/generator, and small motor/generator --
really do all stay locked together through the planetary gear-set,
and everything they do is controlled electronically by shunting power
around between the motors and the battery. Of course that and all
the surrounding electronic gack requires several on-board computers
to run it all, but Toyota seems to have done a really good job on the
engineering side and is far out in front of most efforts that other
automakers [particularly the stupid americans] are doing. The Big
Three in Detroit, in particular, appear to be bringing various
"hybrid" offerings to market soon but they're really only electric-
assist kludges and seem to improve gas mileage by a measly 15% or so.
But everyone seems to really love their Priuses, and I've been
reading lots of internet bulletin boards and such about them. All
fine and dandy, but it's physically still too small a car for my
usual purposes. One thing I discovered is that they've been selling
a hybrid minivan, all-wheel-drive no less, over in Japan for at least
two years now. So I'm starting to make inquiries and push in various
places to get more info about it, at the very least. The alternative,
although not quite as attractive as the minivan form-factor, is the
hybrid Highlander. Unfortunately it's also very overpowered, because
they think they have to aim it at the buys-SUVs-to-compensate-for-
other-inadequacies market, so there's no way it would see the same
50+ mpg. But it might also have that same high geek factor and the
whole adventure of reverse-engineering enough about the computers and
such to make interesting hacks. Anyways, I wait-listed myself for a
Highlander at a local dealership. It's a refundable deposit and
nothing is going to happen on it one way or the other until May
or June, and in the meantime I might find out more about other
alternatives. This is *not* going to be anything like cheap, though,
but I think everyone understands that spending a little more to try
and lead by example is not necessarily a bad thing. Hybrids are a
new but fairly promising thing, and may be something else that gets
people thinking the right way. Either that or they'll just have
their little fad like econoboxes back in the seventies, and then the
american market will be right back to its gas-guzzling antics.
Oh, and you'll be amused to know that at least one guy who hangs out
on some of the Prius bulletin-board/chat sites refers to his car as
Whether I noticed or not, all of the reading had me almost feeling like an
experienced Prius driver already -- knowing all the funny little nits about
its operation and what to expect from Toyota's approach to hybrids in general.
Now, six months or so before all this I had taken a very brief and not very
informative test drive in an '04 Prius, in a blinding rainstorm during last
fall's Altwheels festival. My main beef with it was the "creep" exhibited
with the car in "drive" and no pedals pressed -- why, I wondered, had Toyota
gone out of its way to reproduce one of the stupider and energy-wasteful
artifacts of a standard pig-dog automatic transmission? And slightly
subtler, they also simulate "engine drag" when the car is coasting with no
pedal input. My take was, and in fact still is to some extent, that the
system should be entirely neutral with no "go faster" or "slow down" input
from the driver -- no creep, no drag, nothing. Now, the explanations of
why any of this was done still made some amount of sense -- holding against
rolling backwards when starting uphill, giving a small amount of regeneration
when coasting, and giving the automatic-transmission aficionados a feel they
were already used to. But really, shouldn't I be able to command all of that
with pedal input regardless? Like I do in my manual-transmission car without
even thinking about it? It was fairly likely that a Highlander, or any
Toyota hybrid based on the same system, would act the same way.
So I asked about that into some of the Prius forums, and found the subsequent
discussion quite reasonable and well-informed even though the answer was
basically "that's the way they designed it". But helpful people popped
out of the woodwork to talk about it, and gave the whole exchange a nice feel
of "community" in a way. So I found that I could bounce my questions off
these groups of enthusiasts and get good rational answers. There were easy
workarounds for many of the little operational quirks, so that made it all
sound somewhat better. And one and all they obviously enjoyed the heck
out of driving their Priuses, creepy or not. As that Boston Globe article
would say some months later -- "they get a big charge out of this."