[Vision2020] hypermiling

[Paul Rumelhart]

I've been reading about a practice called "hypermiling" in which you try 
to increase your gas mileage by varying your driving habits.  Has anyone 
else come across this?  It's interesting stuff.  You can make some 
significant gains in gas mileage if you use some of their tricks.  Of 
course, some of them go beyond crazy sometimes, but I'm sure a happy 
medium can be found.  It really helps if you have a computer in your car 
that shows you your current gas mileage and an averaged value.  Some 
newer cars have this, as do some select older models (my 1990 T-Bird had 
one).  I understand you can buy these gauges third-party as well.  I'd 
really like these to become standard on all cars.

The idea is to drive around for a while keeping an eye on your immediate 
gas mileage and seeing what actions have what kinds of effects.  
Obviously, tearing away from a stop sign burns a lot of gas, as does 
driving too fast and driving aggressively.  Slower accelerations have a 
better effect, as well as trying to keep your speed constant as much as 
you can.

Some ideas I've come across:

- Drive proactively: keep an eye out for what is going on ahead of you.  
If you are going to turn left, for example, try to time your speed a bit 
to arrive where you have to turn where there is a gap in on-coming 
traffic.  If a light a ways ahead of you just turned red, slow down and 
try to get there when it turns green.  Speeding up to the light, 
slamming on the brakes, and having to start from a complete stop just 
wastes gas.

- Throw your car into neutral and coast to stops and turns.  Some people 
go so far as to turn their car off, but that isn't usually too wise 
because you can lose your power brakes and steering.  You don't have to 
go so far as to have your car crawl to the stop and not have to have 
used the brakes at all - but even a little bit of coasting can make a 
big difference, especially if your car has low rolling resistance tires.

- Keep your windows closed and your A/C off.  Open windows really 
increase drag, and A/C can put quite a load on the engine.  The weather 
may require you not to go too far with this, but try to keep in mind how 
your comfort is affecting your mileage and compromise if you can.

- If it's raining, drive off-center on the road (along the white line) 
to keep your tires out of the tire grooves in the center of the road.  
Water just pools there and your car wastes gas throwing it around.

Some things that the professional hypermilers do that I don't recommend 
(yes, there are competitions):

- Drafting 18-wheelers on the freeway.  Basically riding their bumpers, 
throwing the car into neutral, and using the pocket of wind created at 
the rear of the truck to move you along.  Obviously, it's very 
dangerous, but it hurts in the long run too because the 18-wheeler has 
to use more gas to move down the highway and your car is probably more 
efficient than the truck is.

- Hitting off-ramps at insane speeds in order to coast all the way to 
the stop sign.  Some of the professionals literally have their tires 
squealing as they go around these spirals in order to coast farther.  
Not really that safe.

- "Pump-and-gliding".  Nothing really wrong with this - but it's hard to 
do without a lot of practice.  There are apparently certain RPM/gear 
combinations that are more efficient than others, so it's sometimes 
better to speed up quickly and coast as much as possible.

- Driving barefoot.  Professionals do this so they can make small 
microadjustments with the gas pedal and feel what is going on.  It's 
probably not that safe, but I don't drive that way so I could be wrong.

Anyway, just thought I'd mention this now that gas prices are going 
through the roof.  Some of these hypermilers see 50% increases in their 
gas mileage or more on a regular basis without going completely nuts 
with it.  The cool thing is that this can help even if you have an old 
gas-guzzling boat of a car.  Every little bit helps.

Paul