I have a 07.5 mega cab laramie with a 6 speed auto and 410 gears.My truck is stock with 10k miles on it.My in town mileage is 13 mpg and highway is 17mpg.If I hook up my lawn trailor about 4000 lbs I get 10 city and 13 highway.My question is,is this normal ? It seems i should get better mileage specialy pulling a light trailor.

 

I'd say its normal. I bet you'd get the same towing mileage with a 10k trailer.

 

That's not bad at all for a 6.7. I have truck in signature with 5.9/4.10 auto and that is what I get exactly.

 

If you don't mind me asking, what kind of RPM's are you turning? I would think that 4.10's would be a better choice for the six speed auto tranny trucks.

 

All other things being equal, how much would the mileage change if the 6.7 with the auto had a 3.73. rear vs 4.10 ?

 

george colvin,

About 1-2MPG, Average.

Keep the RPM under 2K and you will see better MPG regardless, over 2k, either gear ratio, and the MPG falls fast........

Stealth

 

Thanks for all the feedback.Iwent through all rhe codes and a new turbo @2500 miles and a few flash recalls,but I havent had a problem since.Im thinking about the ts mp8 for fuel mileage,but I dont want to hurt the trans or anything else.

 

I did check the rpm's this morning, 1800 @ 65 mph.Not as bad as you would think with stock ,short tires and 410's.

 

The best I've gotten with 3.73 is 17.1 on the highway solo at 20,000 miles.