Sixteen Tips to Improve Your Jeep's MPG
We're constantly looking to eke more mileage out of our Jeeps. Gas prices are high, that's no secret. The more gas we have to put in the Jeep, means less money for upgrades and wheeling trips. We've decided to point out the pros and cons of some of the most popular gas-saving tips and tricks.
There are tons of widgets and get-free-gas-quick schemes that some companies use to suck the money out of your savings account. At the end of the day, you can break it down into several categories: gas-saving modifications or maintenance, altered driving style or technique, random junk or miscellaneous. We'll show you our top picks for each category.
Gas-saving modifications and maintenance tips Sure you can justify these things as saving gas. However, just about any one of them will cost more money than what your savings account realized it would in fuel economy. That's OK, though. We still do most of them.
Whether we are talking about the rotating mass of a tire/rim combination or the extra chili dogs and beer you had for lunch, losing weight means better fuel economy.
Pros: Less weight means less work for the engine to do which equates to higher efficiency in using fuel. Lighter tires and rims can play a big part.
Cons: Lighter tires are usually not as puncture-resistant. Plus, we really like chili dogs and beer.
Swap in disc brakes. It's OK, we told ya so.
Pros: Less weight than drums and less parasitic drag than a drum-brake system. As a bonus, mud won't cake up in them and eat away your shoes.
Cons: The money you save in gas will never make up for the expense of the disc-brake swap.
Put in a high-output coil, and increase your spark plug gap.
Pros: More complete combustion comes from the longer arc passing through the mixture and igniting more fuel per spark.
Cons: Gains on this one are under one mpg, unless its time to replace the components anyway. Then you can show the other significant increases.
Align your Jeep properly.
Pros: Not only will you end up with decreased tire wear and save cash that way, but without a huge toe-in from that last rock your tie rod ate, you'll pick up a mpg or two.
Cons: To make this worthwhile you'd need to have your Jeep aligned after every wheeling trip and major pothole. Just check it once in a while with a tape measure, and if it's out by more than 1/4 inch, take it in.
Switch to less-aggressive or properly sized tires.
Pros:With less-aggressive tires, your Jeep will have better on-road manners. Also, it will be cheaper to replace tires than those huge mud tires.
Cons: Jeeps are geared for those huge tires, and smaller ones will contribute to losing mileage. Also, one off-road tow bill ruins any savings in the tires. Ditch the 2-bbl carburetor, put in a 4-bbl one.
Pros: Better fuel economy through more efficient idle and off-idle circuits.
Cons: There isn't a single person we know who can keep their foot off the stupid pedal with a good 4-bbl and its properly dialed-in secondaries.
Some of us here have realized some significant increases in mileage by changing their oil.
Pros: Gains of almost 40 gallons on a tank of gas in an '00 TJ.
Cons: You'd have to be as negligent as Editor Cappa and let your Jeep go for almost 20,000 miles with dinosaur oil in it before you'll see gains from an oil change. He claims he saved money by using the old engine oil as gear oil.
Carburetor return springs.
Pros: In addition to bringing your idle down, you'll build up some decent calf muscles. Add springs for more advanced workouts
Cons: You will start walking around with a tilt due to only exercising the right leg.
The old acetone trick. (See lead photo.)
Pros: We ran it for almost 5,000 miles in our project YJ. While the initial mileage increased, subsequently running it with or without the acetone did nothing.
Cons: We think that the initial mileage increase was just due to the acetone cleaning things out. Use regular injector cleaner every oil change, and you won't smell like nail-polish remover whenever you fill your tank.