mine is kinda the same way with the 4:10's it dives off hard if I go over 70 80+ and its down into the 13's.

when I ran 3:55's it didn't car 80+ and it was still high teens.

Diesel Rod

 

This is bass ackwards for me too. The reasons are quite obvious. The 4:10 gears, the 75 to 80mph, and the bigger tires. With 3:73 gears, your mileage starts to drop when you go above 60mph. With the 4:10's, I'd say it drops off even quicker. That also explains why you do so well in town, you don't work the engine with those gears. What we all need are 2 speed rearends!

 

[quote=CampSpringsJohn;7942167] That also explains why you do so well in town, you don't work the engine with those gears. {/quote]

when I had the 3:55's I got the same as the 4:10's in town. the 3:55's were killer on the HWY but sucked in town. the 4:10's are just the oposite.

3:73's or a two speed would be nice. 4:10 to a 3:23 or taller, 3:08.

Diesel Rod

 

when i bought my truck it was bone stock. same as it came from the factory. nice toyo street tires on it. got 24 hwy 20-21 city if i could keep my foot off the throttle. when i installed my new exhaust and intake could get 26-27 hwy.

 

26-27 MPGS!!!!

That's unreal. That puts me to shame.

Surely it's not 4x4, or is it? rear end? tire size?

 

4x4 xlt auto quad cab. im not sure what the gears are. i believe there 411's but i know its a posi! it pulled my gooseneck and chevy mud truck on it with no problem. couldnt even tell it was there unless some A** hole pulled out in front of me! (bad day). i also have propane injection now so with the new injectors (stage two) im still getting 22 mpgs. tires are toyo a/t's 245/85/16 i think. cant remember off the top of my head

 

Were you hand figuring the mileage, or going off what the truck computer was telling you? I have heard of a couple folks getting close to this kind of mileage, but they were in 4x2 trucks with manual transmissions. Congrats on getting those numbers. Those are just extremely high compared to most everyone else. I can't help but wonder what made your truck, and a couple others out there, do so good compared to other trucks.

 

I second that, get the aftermarket guys working on building us one.

 

it may be the the location. im in the desert in New Mexico. idk if that has anything to do with it