[rockwe31]

Make sure you are using factory sized tires, have all your regular maintenance caught up, and drive slow lol. 20 mpg is great from an early 00s SUV. There’s no magic mod for better mileage.

 

[rockwe31]

The early 00s were the gas guzzler era; think Hummer, Ford Excusion, etc. Gas was cheap so there was not a big emphasis on gas mileage when producing vehicles. Now there’s a much bigger emphasis on gas mileage. Aerodynamics are improved, smaller and more efficient engines are used, tech such as active fuel management and auto stop/start exist. With almost any 20 year old vehicle your expectations for gas mileage and performance have to match that of that time, not the present.