My '92 F-250 with 351 had been getting about 10 MPG. I took it to reptuable shop, with tons of computer testing equiptment to see what they could find out. They ran a TON of tests on it, and everyone came back fine, good spark, good emisions, good timing, good compression and some other stuff. The mechanic suggested that they run a Motorvac treatment system through it, but would make no guarentees. So I said, ok go ahead and do it maybe it will help. So they hooked it up to the machine for TWO HOURS, this is a procedure that normally takes about 30 minutes. Supposovly the injectors in cylindars 1 & 2 were leaking but sealed themselves with this treatment stuff. Haven;t has a chance to run it and check the fuel milage yet, so does anyone know weather or not i should expect any improvment?

my 302 gets about 12 to13 mpg in town and a little better than that on the highway. check you egr valve.

Today I got to try it for the first time. Previously I got 9-10 MPG, but today I drove a considerable distance and filled up when I left and when I got back and checked the milage. I was very pleased to see that I got 16.3 MPG!!! I must say I am quite pleased with the results.

I can now afford to leave home! LOL

That's pretty tall mileage for that vehicle.Do you have dual tanks?How many miles did you travel when you checked it.What I'm getting at is a possible cross-over problem,if not,congratulations.. Huh, wonder if my 460 would benefit--Nah, wishful thinking on my part.

I drove about 50 miles, which isn't real far, but I know it would not have got that kind of milage before it was flushed. The previous owner did tell me that it was not umcommon for it to get 16-17 MPG, so i guess he wasn't lying.