78 Ford with a 93 Dodge 12v and A518 running a divorced 205, 4.10s and 35" tires. 150,000 on donor. 3600 spring, ground pin and free mods. 4" exhaust and BHAF. 70-75mph in mountains got me 13.5mpg on first leg of our Christmas trip. Slowed to 65 and kept EGTs under 800 for second leg. 13 mpg on flatter ground. WTH?

Trans shifts ok but is very mushy. Plans for Goerend stuff after Christmas. Would old injectors kill economy? Anyone had an A518 sloppy enough to cause that low of numbers? I've gotten as high as 19 and as low as 12. Thanks.

 

either could cause low mpg.

 

The stock torque converter is mushy like a bowl of oatmeal, to protect the trans.
I put a DTT high efficency converter in mine and beefed up the trans, it was like night and day.
But your rig and that kind of driving is not a recipe for economy...

Good luck, Joel

 

Thanks guys. Yeah I know it'll never get 30mpg like most Cummins trucks, but I know it'll do better than 13.

I'll check into injectors and do the trans ASAP.

 

i know when i built my trans i got better millage...i believe it was in the converter but the valve body was modified also

 

Rebuilt transmission only helped my 92's fuel mileage slightly. Went from 16 to 18. With 150K on your injectors, I'd not be in too much of a hurry to blame them. Check for boost and fuel leaks.
The Cummins just may not like being in a Ford

 

i like the first gens...but cant stand the dodges after that...guess im just old school leaf springs, serviceable wheel bearings and hubs
i guess thats really all dislike is the front ends...just feel all over the place when towing too. just my 2 cents not tryin to start and arguement

 

The first Cummins I ever drove was a 2 ton Ford. I think it was new in 84. Man was it slow. I still managed to get a ticket in it though