What is the best quality gasoline for best MPG for my 2004 Jeep Liberty?
There is not a really big difference in gasoline quality. Your Liberty will get about the same mileage no matter which brand you buy or which octane you use. The engine can only benefit slightly from the higher octane fuel because it doesn’t need it. I used 87 octane in mine and about every 20,000 miles I added a bottle of fuel injection cleaner that contained NAPHTHA. There many injection cleaners on the market but only a few have naphtha and the others are no better than a bottle of mineral spirits. If the gasoline you buy has ethanol you probably won’t need the naphtha. For best mileage, go easy on the gas pedal, no jack rabbit starts. Keep tires pumped to maximum, and change air filter to a low restriction type element. If you have cruise control, use it, it will save you gas except on hilly roads. In winter, the defroster mode will run the air conditioning pump to remove moisture so only use defrost as necessary. Mine usually got 18 on highway driving at the max which was a bit le