Hi,

By "hypermiling" are you referring to trying to get better fuel economy?

If so, you MAY find a SLIGHT increase by upping your tire pressures 2-3
lbs over the sticker. In my own experience, this can help a tiny bit w/o
sacrificing ride, and usually improves handling a bit. Much more than
that doesn't seem to produce worthwhile results in everyday driving
(there ARE reasons to go much higher, but they're for specialized apps,
like racing/autocrossing/etc.)

Light oils, especially synthetics? I've gone back and forth on this idea
since the late '70s, and have yet to see enough of an improvement in
fuel economy to convince myself it's not just a normal deviation (I've
always kept very good fuel records.)

Best way to cut fuel consumption? Drive less, and drive slower when you
must drive.

Back in the '70s when we had the mandatory 55 mph speed limit in the US,
it was estimated fuel economy could be as much as 20% higher at 55 than
65 (a lot depended on the vehicle, of course.) I've always driven
"economy" minded vehicles, and couldn't honestly say I saw that great an
improvement back then. However... since that time we've increased our
average driving speeds a lot, and our driving "style" has changed a lot,
to "jump on the throttle, jump on the brakes" even out on the freeways.
On a trip last weekend of about 550 miles, I had the opportunity to
"slow down and cruise" as it appeared $4 gas is starting to get people's
attention. The vehicle I drove has returned just a hair over 25 mpg in
mostly all freeway driving the last 35k miles or so, and it really
doesn't range that much above or below this figure--very rarely it will
reach the EPA estimate of 27 highway on a longer trip. This time, I
"went w/ traffic flow" (up to 75 mph+) halfway, then tried to hold my
speed to around 60 mph as much as possible on the return. The trip
returned a hair over 29 mpg overall. And for all those folks who think
they're "in a hurry," the travel time was all of 9 minutes longer coming
back than going...

So... you pays your money and you takes your choices, but slowing down
and holding consistent speeds will do you the most good if it's just
better fuel economy you seek. Even in a car that's not exactly the
econo-champ of the marque!

Rick

Hi Peter!

I'm gonna have to chime in with Rick on this one; ya shouldn't have
bought a Rex if you couldn't afford to feed it. Absolutely best-case
mileage you're likely to see (I used to have one) is maybe 26-28MPG,
(2.0l, the 2.5l isn't even gonna be _that_ good) and that's highway
with a very light foot . And what fun is that?

Your best bet for economy would be to trade the WRX for a 40+MPG
Tercel or something (and what fun is that ;-), or maybe buy an
econo-box beater of some sort for the daily grind, and save the WRX
for weekend fun.

And I guess, if you want real answers to your questions:

Engine oil also lubricates and, to some extent, cools the turbo. I'd
be real hesitant about straying very far from the recommended 10-40.

Yes, dramatic over-inflation will cause the center of your tread to
wear faster, as under these conditions it's the only part of the tire
in contact with the road. For the same reason, traction will suffer.

You might try fitting a taller, skinnier tire with a summer/highway
tread pattern; that might get a couple more MPG. You might try
tinkering with the boost control so that it comes on at a higher RPM,
or even limiting boost to less than the factory 7 or 8lb (can't
remember if that's the correct number for the WRX, or maybe that was
for the older Legacy turbos, but you get the idea). You could probably
figure a way to disable the drive to the rear, that would probably
gain a little, too. But by now you're basically driving a Tercel, or
perhaps a 1.8l FWD Impreza . . .

Sorry to be the bearer of bad news, but it takes fuel to make
horsepower. You just can't have your cake and eat it too . . . alas.

ByeBye! S.
Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

My 04 outback loaded down with 2 adults , 1 child and a 115 lb dog
plus gear managed to turn in 29 MPG on a 3400 mile round trip.  I
tried to keep it at 70 as this speed seems to turn in reasonable
mileage .