So I recently traded in my Impala for a 2006 Sonata. It’s about 30% more powerful, but lighter, and therefore gets only slightly worse mileage. But with gas prices breaking the $3 mark, I’ve decided to take up a new practice known as hypermiling.
Hypermiling is an emerging trend where drivers tweak their driving habits, and many times their cars, to squeeze every last ounce of mileage out of them. In some cases, simple driving habit changes have resulted in up to 50% increases in mileage over EPA estimates.
I’ve always beat EPA estimates on city mileage (EPA estimated 20mpg on my Sonata, and after going through my first tank of city-only miles, I got 21.6), but never been able to quite match the estimates for freeway mileage. So when I heard numbers like “50% higher than EPA estimates,” that really intrigued me, so I thought I’d look into it. Since I’m not about to start trimming crap off my car to make it lighter or remove pieces off the body to make it more aerodynamic, I thought I’d go with the driving habit changes. Here’s what I’ve decided to try:
Max out your tire inflation – The maximum rated inflation on most passenger car tires is 44 psi. I’ve always run at 35 psi, so I’ll be bumping that up. During the winter I’ll lower it back down to improve traction in snow and ice, but that won’t be an issue during my test.
Highway drafting – Tailgating an 18 wheeler is the best way to go. Problem is that it’s really dangerous (and illegal). So the recommendation is to follow about 10 car lengths behind. I’ve drafted off of big trucks before, but they usually are driving so slow that I can’t stand to follow them for more than a couple miles. If I can be patient enough, maybe I’ll do it longer. Be careful not to get in the spot where the air comes down right on top of you. The turbulence will actually worsen your mileage.
Shutting off the car when waiting – Back in high school, I read that starting your car requires gas equivalent to 30 seconds of idling, so I’ve already been shutting off my car in fast food drive-throughs and red lights when I know I’ll be waiting a long time. But I just learned that modern vehicles only require gas equivalent to 10 seconds of idling to start up. So it looks like I’ll be shutting the engine off more often. My only concern is the wear and tear on the engine and starter motor.
Never backing up – The trick here is to always pull forward into a parking spot that allows you to pull forward to get out. I question whether the time spent looking for a spot to do this with negates the advantage. On the other hand, I generally park out in the boonies just to be away from everybody else, so I guess this won’t be too difficult.
Slow accelerating – This will be the toughest for me, but I’m going to try.
Approach red lights slowly – This conserves the motion you create by trying to keep the car moving, never actually coming to a complete stop. It takes some practice to learn the timing of the lights in your home town, but this is something that I’ve already been doing for years, and started doing more seriously and consistently for about a year now.
Drive slowly in rush-hour traffic – The idea is to maintain a constant speed rather than the stop and go most drivers do. I’ve actually been doing this already for about 14 years now. Most people have a hard time because it can leave a large gap between you and the person in front of you. Most people can’t stand having other cars pull in front of them, or they feel like they will reach their destination faster if they ride the tail of the guy in front of them. Think logically instead of emotionally, and it’s easier.
Coasting when possible – When I visit family out at Strawberry Reservoir, there’s this huge hill I pass over. I’ve coasted up to 8 miles down the long side. The recommendation is to shut your engine off when coasting, but doing so means you lose power brakes and power steering. I’ve shut my engine off in a coast a few times (I used to do it a lot when I was 16), and I guess it would work for approaching long red lights. I’ll try it more often.
A big concern is doing all these extra actions increases distractions and can result in a nasty accident. And the whole idea of coasting with the engine off… not a particularly great idea. So I’ll only be doing most of this stuff when it’s safe with few or no cars around me. But I’ll let you know how my mileage goes.