The rpm is where it should have been to begin with. Fuel economy is is going up. Now all i need to do is put a set of 285s and the truck will be perfect. I hope going from 3.73 to 3.42 does not make me a POSER.

 

Keep us informed on how it works out.

MikeyB

 

What rpm's you running at 70 in 6th? Just curious. Thanks!

 

I am running 2000 rpm @ 70, 2150 @ 75 and 2300 @ 80.

 

I dont know how it would make you a poser running any gear youd like. Its your truck, right?
I know there are a lot of people who would like to do this, but the majority are 4x4s and the price is pretty steep to save a couple MPG. Im hoping my '04 will do a bit better with 315s instead of the 265s. I know in town, its getting 17-17.5. Its out on the highway that the 4.10s really start to wind up over 65mph. I just cant drive that slow...

 

hotrodk already beenthere and done that with bigger tires. you will loose too much fuel mileage and low end, and only 50psi max. don't go with 315's for that reason. maybe 285's at the most and keep em at 70-80 psi you will be better off. most people put 315's on for looks. later

 

i have 285's on my truck-dealer did the flash for the bigger tires. i have the 3.73 rear end and the 48re and i run around 1900 rpm's at 70mph

 

How is it for pulling a trailer?

 

I have found the perfect tire. Some of you guys already run it. Its the Toyo Open Country A/T 285/75/17. Perfect width, and height. Whatcha think?

 

I just spent 7.5 hours driving down to dallas singing 2,200rpm the whole way, I'm also running 285/70's and the whole way, all i could think about is 3.42's a tad taller tire but not wider, and the dynatrack. I think a man could get about 5-6mpg out of that combo. All it takes is money... but, i'd also like to know how it pulls b/c even though i don't pull right now. In a few years i'll be pulling quite often.

 

I towed about 7500lbs to Philadelphia MS last week with no problems. I know thats not alot of weight but the truck did great. Guys keep in mind, i have a 2 wheel drive truck and the installation of gears did not cost me anything.

 

People with auto's are okay with 373's, people with standards are wishing for another gear.
At only 100 KPH (62MPG) I'm revving 1900.
I might try 315's on H2's next...

 

I run 315's with a 6 and 3.73's. Some say it takes away too much power but it works perfectly for me. 2050 at 120kph (78mph). If I'm pulling anything extreme, I use 5th for hills and the 315's raise that rpm just right. Flat doesn't seem to matter much unless you get down below 100kph, then rpm is down to 1650 and starting to lug a bit if loaded heavily. 315's in 1st to start really doesn't matter.

315's change your effective ratio to 3.5.

Cya

 

Billie, how fif the 315's affect your MPG?

 

I don't do hand calc regularily but the overhead stayed about the same without the ECM flash for tires so it appears like a 10% gain since the mileage adjustment is 10% (actually 9.something) The BFG 315's are 35" tall from the 32" 265 stock. FWIW, the overhead reads 19-20 city hiway.

Cya