You'd be amazed by how difficult it is to find information on the internet to support this node (though I finally did, thanks http://www.epa.gov/otaq/17-tips.htm). Whenever we talk about conserving gasoline, we talk about avoiding or minimizing driving as an activity altogether. In other words, don't drive if you don't really have to, and carpool or ride the bus whenever necessary. Nobody seems to be concerned with how we drive, they're more worried about how often we drive. Here are some basic tips that can go a long way towards improving your fuel economy:
- Whenever possible, avoid coming to a complete stop. Don't rush towards stoplights, instead slow down and coast (unless traffic is bad). All it takes is a little depth perception in most cases. When your car is at a complete stop (idling), your fuel economy is exactly 0 miles per gallon. The act of getting your car to start from a complete stop has a dramatic impact on your fuel consumption, which is why "highway" fuel economy is always better (despite the higher speeds) than "city." On the other hand, don't be annoying about it. In bad traffic, this can really piss people off. Blowing stop signs might not be a good idea. But the idea is to keep your car moving as much as you can. Even if you're only rolling at 5 mph before the light changes to green, you're still saving gas by not stopping entirely.
- Stay off of your freakin' brakes in general, whether in the city or on the highway! Nothing annoys me more than a brake-happy fool who constantly taps their brakes and then re-accelerates, oscillating between 55 and 65 mph depending on the ebb and flow of their cell phone conversation. How counterproductive is that? Try to use your brakes and accelerator as little as possible (see the end for more on this). Stay at a constant speed, don't fall below your desired speed or you'll have to waste energy speeding back up. Use cruise control on long drives (assuming you have it, that is).
- Minimize the amount of weight in your car. The more shit you're lugging around, the more energy you're wasting. It's a simple fact that it takes less effort to move less weight. It's probably not a good idea to dump your spare tire, though.
- Keep your car in good working order. It's a good idea to change your PCV valve, crankcase filter, and air filter at least every 12,000-15,000 miles. Change your oil at least every 4,000-5,000 (the 3,000 figure is more of a conspiracy to get you to buy more oil than anything else) miles, more frequently depending on how hard you drive. Change your spark plugs! Get tune-ups! A bad sensor can ruin your fuel economy. The better your engine works, the more efficiently it burns gas. In many cases, a faulty brake system can drastically decrease your economy. As brakes begin to deteriorate, they often have difficulty completely disengaging, meaning you must drive with un-needed, added friction. Drum brakes can be especially prone to this, as the springs that engage/disengage braking can become old and weak.
- Don't drive like a bat out of hell. In many cases, accelerating quickly is entirely pointless. Granted, it's fun, but you'll do much better to gradually accelerate.
- Avoid speeding. Yes, it's fun, but supposedly you can improve your gas mileage by as much as 15% by going 55 mph instead of 65. The more often your engine is revved high, the worse your economy will be. Of course, if you have enough torque, you might be able to do 65 mph at 1500-2,000 rpm.
- Check your tire pressure often. If your tires are abnormally low, your engine must work harder to travel an equivalent distance, thus reducing your fuel economy.
- If you drive an automatic, use overdrive (if you have it). If you drive a stick, try to stay in a higher gear whenever possible. The less your engine is revved between shifts, the better. Of course, you can overdo this and cause bad carbon deposits to build up in your engine. Find a comfortable medium between peeling out and stalling out.
- Reduce drag whenever possible. If you're driving a 1984 Honda Civic, chances are you will never reach speeds high enough to necessitate the added downforce a spoiler provides. Instead, it will serve as a source of added drag during normal driving conditions. Also, it adds weight. Whee! Cutting off your side rear-view mirrors can reduce your drag by as much as 20%! Of course, it's most likely highly illegal, although many cars don't have one on the passenger side anyway ...
The most important factor in your fuel economy is your choice of car; the second would probably be how you choose to drive it. I am seriously considering a Honda Insight myself, although I am kind of afraid of tiny sardine-can cars that weigh less than 2,000 lbs. On the other hand, it gets incredible gas mileage, and it lets you know how you're doing at any given moment (which my girlfriend's dad's Ford Explorer is also capable of, although it has to be less gratifying to see "13 mpg" 80% of the time).
Wintersweet had the following additional advice:
- If you're going over 45 mph and it's hot, you are actually better off using A/C because the efficiency loss due to drag caused by open windows exceeds the efficiency loss caused by powering the A/C compressor. Makes sense, since open windows DO create a ton of drag.
- By overinflating your tires by about 2 psi, you can improve your efficiency by as much as 10%. This is safe, she says, because manufacturer recommendations are for a softer ride, not necessarily a safer one. So you'll gain up to 10% and might have a slightly rougher ride.
sleeping wolf had this to say:
"I actually recall reading about a study by Mercedes-Benz that says that the best way to cut fuel economy is to stomp on the gas when you need to (and then coast)."
If you allow yourself to coast too much (to where you fall below your desired speed) you will have to waste more gas by depressing the accelerator. So the best strategy would be to gradually reach your desired speed (no stomping) and then to maintain speed by lightly pressing the accelerator whenever necessary (basically what cruise control does). I didn't mean to say "stop braking and accelerating as much as possible" in the sense that you should fall below speed; rather maintain a constant speed as smoothly as possible.
Finally, a tip from bigmouth strikes:
"Another thing to save fuel is to always use engine braking. Doing so, the car's momentum drives the engine and NO fuel is consumed. Better than idling, thus. Can be used on automatics as well as stick shifts."