I saw a fella on here the other day post that at 70mph, you should be sitting at 1900RPM with an auto if you have 3.73 gears...so since I am at more like 22-2300 or so at 70mph, would that say that I have 4.11s? I have the stock Michelin 265s on her, by the way.

Derek

 

I think you're right.

 

4.10s not 4.11

 

Mine reads 70 MPH @ 2K RPM on GPS. The speedo is off by 1.5 to 2 MPH
I have stock rubber with the 3.73`s. 4.10`s would be what you have based on tire size and RPM`s...

 

So I guess that tells me why my best tank was around the mid to high 500s on the highway then...hehe...and to think, this whole time, I thought I had 3.73s being that it is a "California truck"...Oh well, I kinda like the idea of 4.10s(sorry about that 4.11s post)...it should be better for pulling the gooseneck when I go home. Thanks ya'll...

Derek

 

Yeah...4.10`s tow better....

 

well mine is a six speed manual and at 70 it is turning about 2250 and i have a 373 rear

 

Isn't 6th gear on the newer 6-speeds kind of low?

I have 4.10's and a 6speed, and at 75 I'm turning 2500RPM.

 

So what gearing is better for the highway when towing. What tire size should a person run for better MPG?

 

Way to low for me

 

3.73 better for fuel mileage... 4.10's are good if you drive about 60. But they're better for towing. Of course I don't tow much.

 

My dad just bought an 07 mega cab, 2500, 6 speed with the 3.73 and the dealer mechanic said that dodge lowered the gear ratios in the 6 speed transmissions and raised the ratios in the autos. Has anyone else heard this?

 

I heard or read that in one of the forums here. It sounds like the new 6-speeds don't really have an over-drive? From what I've read, you can't get 4.10's with a 6-speed anymore. But I might be wrong on both statements above.

 

So better mpg-373. WHat about tire size, brand, tread ect???

 

You can only go so big on tire size before it will hurt your mileage. More rotating mass = more power to turn it. The best tread for highway mileage IMO is a highway rib or something similiar. I'm going to have to check my sticker again because I'm running about the same RPM as you guys with 4.10's and I was almost positive I had 3.73's.