Numbers are from: 75-80% Highway Driving / Fill-ups at same gas pump

Factory: Under unaltered driving conditions...varied from 17.0 - 18.5 MPG

With UltraFlow single 3" exhaust, K&N FIPK, and Chip added: No actual increase, but did hold steady at 18.5 MPG

With Power Pulleys added: Instant and steady increase to 20.0 MPG

 

That's a great increase from the pulleys.

On my '95 5.0 I got about .5 mpg, but that's it. Most of my driving is around town. I had also installed a Jacobs ignition and got good mpg gains.

I haven't really tracked as close since I put on my cat back (Gibson) at the end of last year. No big gains, as I would have noticed if that was the case.

I have seen posts of good gains with exhaust work, but in my years I've never seen more than a small (1mpg or less) gain from exhaust alone. I imagine that like anything else all the weight, gearing, driving style, etc. variable will dictate which mods will help the most.

As for pulleys, they are about the best bang for the buck you can get. What else can you get that gives you 1 HP for about every $10-12 bucks, and also lowers operating cost?

 

on my 85 bronco with a 302 5.0L running on 35x12.5 super swamper ssr and 4.88 gears i get 10mpg in city and 12.5 highway. my speedo is correct says my GPS