I just bought a stock 1990 D250 4x4 auto. Wondering what easy (aka cheap/free) modifications I can make to improve performance, mileage, etc. We do NOT have smog testing here. Can anyone provide some insight? I'm a new Dodge owner, and my other trucks have all been 1983 and older... I'm still trying to learn the newer stuff (although 1990 is 25 years ago already!).

Thanks!

 

Free up the Intake and exhaust. Improving performance is counterproductive to improving mileage. Decide which was one is more important to you.

 

Lose the cat, add true duals.

K&N air filter or the like.


Should be good for 25 more hp right there.