Saturday, June 28, 2008

10 tips for better fuel economy

With gas prices going ever upwards, I thought it timely to add a new page to my site. 10 tips for better fuel economy. Enjoy.


Anonymous said...

Other things to consider are reducing weight. If your car is full ok junk most of the time giving it a good clean out can help. Also makes your car go faster. :-) Things like your spare wheel can be replaced with a seal canister etc.

Lightweight alloys can help to reduce rolling resistance further as there is less turing force required to get the car moving.

Block gear changing using as few gears as possible to get up to speed is another good way to save fuel.

Should also mention how useless most aftermarket devices and in tank solutions to improve mileage are.

Chris said...

Good tips. I'm building up a second page for reader-submitted tips.

Anonymous said...

I've remembered a few more :-)

A couple of web sites suggest using a length of hose/ducting to build a warm air intake so that the car draws hot air from the radiator.

The premise behind this is an induction kit in reverse, warm air has less oxygen so burns less fuel.

Never seen this done though.

Also swtiching to using thinner/synthetic oils can help to reduce friction as well.

Rolling windows down/having air-con on full makes a difference.

For those buying new cars especially in the UK with diesel being 15p/L more expensive it might be cheaper to run a petrol with a lower mpg than a diesel, and more fun too. :-P

Ok I'm done :-)

Joely08 said...


A warm air induction? I'm no car expert or anything but it seems it would burn more fuel because there is less oxygen to ignite therefore to make up for the reduction of oxygen the engine will burn more fuel.

And for the windows up.. I think in the city or when your not driving fast it saves more fuel by having the windows down. That's just my two cents worth.

I also want to mention this idea of "hypermiling" I've seen on CNN. It's interesting but looks like it would be tough work. lol.. I've done a few techniques of hypermiling before like costing in neutral with the engine off but I only did it once because I think it seems unsafe because the power steering, ABS, and etc. goes out as well. So I never tested it long enough on a take to see if the average person can use it. But the people on TV claim they can kick out 50% more MPG than the EPA's estimate.

Chris said...

You're right about warm air induction - it wouldn't do much to help. Cold air induction would but that requires a cold air induction kit to get air from somewhere other than the engine bay. The colder the air going into the engine, the better. Cold air = dense = more energy per volume.

Anonymous said...

Chris, your take on block gear changing starts off with saying, roughly, that a manual gearbox is better than an automatic. Very roughly.

Are you sure? I always thought that because automatics were programmed (mechanically or electronically) by people who know way more about gear shifting and fuel economy than most people do, they'd be better on fuel than manual gearboxes.

I pretty much always drive in low gears unless I need to speed up or otherwise push it, and I coast in gear. Also, I think it was out of laziness that I started skipping gears (block gear changing) a few years ago. So I suppose I'm better on fuel than most people (except for the occasional planking for fun) with manual gearboxes.

Don't automatics do these things?

Also, out of increasing laziness I'm not always using the clutch anymore. Does this make any difference? I suppose there's something to be said for not clutching as it wastes energy, but sitting in neutral to adjust the speed of the engine seems like the same thing.

I think a lot of this stuff makes little difference, really. Intuitively, I would say reducing weight is the best thing most people can do.

Chris said...

Manuals are typically more fuel efficient because they have a direct mechanical connection from the crankshaft to the wheels through the gearbox. An automatic uses a torque converter which is a lossy component that wastes power because of its design. That's why you can step on the brakes in an automatic and bring the car to a stop without using a clutch.