How to save gas for a 2002 jeep liberty?

By swamping it for a honda civic. LOL

By putting a lot of money into aftermarket parts, you might gain 1mpg if you’re light on the throttle, but for the cost, you can get $2K in fuel as it’s not worth the money.

Liberties came from the factory with synthetic axle fluid and transmission fluid. The best thing you can do here, is to keep the tires properly inflated so drag is minimized, and change the engine oil over to full synthetic. You can drove easily twice as long on synthetic oil, and it’s only 1/3 more expensive. Any major brand will serve you well! If you burn oil, going synthetic isn’t a wise choice, as tops ups will get costly. Also, remove any extra baggage in the vehicle to reduce weight. If you have a roof rack installed with cross bars, remove the bars to help in reducing drag and to get better mileage.

It won’t be noticeable overall, but at the end of the year I can say if you do all the above, you might save $100-300 in fuel depending on how much you drive the vehicle, and the only overhead here is the synthetic engine oil (oil change will run about $65-75) and should only be required once per year, or 15K. Amsoil oils allows a 25K change interval and the oil should cost only another $5 more, so if you drive a lot, Amsoil is the one to go with. I’ve been using it for years on my ’00 Durango R/T and tow a heavy trailer on weekends and I’ve had no problems with it since new.