I just bought a 93 Explorer and I love it. The truck has been well kept and great maintence records have been kept as well. It has a 4.0 and an auto.

The fan is loud on pull out and it gets about 16 mpg. I would like to boost the milage to about 20 mpg. My first thoughts are split fire plugs and a K&N filter.

I'm open to all suggestions

 

Put an egg on the throttle. Don't break it.

A chip will not accomplish this goal (read the FAQ at the top of this section concerning this). Split fires are a good way to throw away your money.

 

Good luck. I had a '99 B4000, and the fan was always that noisy. I averaged 17, no matter what kind of driving I did.

 

Try ussing some qulity injector cleaner like Lucas, it might also help with a truck that old