Your bigger tires give you a lower gear as well....you are closer to 3.55's now depending on your tire size.

 

i get 23mpg 94' reg cab 4x4

 

Yea, I was getting better when I had the 35's on there.. I put smaller tires on because I got them for free from a friend.. dropped me a MPG or two.. . Definitely going back to the 35's soon.

 

ya with my 35s i noticed my stop &go and city trafic mpg went down to 17 from 19 but my highway went up to 23 from 21

 

wish i could get over 20 mpg like some of you guys

 

I get around 15 with the mods I have, but I'm really light on the skinny pedal due to **** breaking all the time.

those 4:10s are definitely hurting you. You could try cruising at around 60mph and see if it helps you a lot.

 

Would slipped timing have that much of an affect on fuel mileage?

 

I would say so

 

it could. if you can find yourself a good diesel mechanic they can probably tell you if your that far off by ear.

 

Dont feel bad my 97 2500 is only getting between 10 and 14 i dont know whats wrong with it i have checked everything. It used to only get lik 15 with street tires now i have 33s and it gets about 13 onlly bumping my timing will help. But how many gallons does my truck hold, i thought it only held 24 but i could be wrong.