I have noticed on my new truck the rpms are higher. Around 70 im running between 2200 and 2300 rpms. Did they change anything from the 06s? I mean this thing would probably redline at 100.

 

Mine DOES redline at about 100...Get it up there all the time.

 

The 06s and 07s should be the same. I was pretty suprised the first time I got it on the freeway.. My 06 with the g56 ran about the same rpms as you mentioned until I got bigger tires. The 315/70/17 BFGs bring thr rpms down quite a bit.

 

How much did the 315's bring your RPM's down? Did you have to do any mods to accomodate them?

 

same rearend in the 07 as in the 06 right?

 

From what I understand the Overdrive ratio was lowered (numerically) making the rpms the same as a 4:10 with 3:73's installed. Thats why you can't order a 4:10 with the G56. You can with the Auto, I understand.

Dave

 

I just traded in my 06 auto for an 06 Mega Cab 6-speed. And I noticed the same thing, 70 the rpm's are anywhere from 200-400 higher. I think that CoastalDav is correct in what he said.

I was told that the only thing that changed from 06 to 07 (besides the motor of course) was the tailights, badging and the front bumper a bit.

 

aight 10-4

 

If you put 315 tires on your truck you would drop your ratio to 3.45. So with close to 30 points off the ratio I am sure you will see lower rpms. My truck drop 200 rpms at 70mph when I went up to 33's

 

D-roc

If I remember correctly, the rpms dropped by about 250 to 300 @70mph. It was hard to tell exactly how much at first because the speedo was off because of the new tires. (I didn't reprogram for larger tires until about three weeks after I got them.) I do a lot of freeway driving so the new taller tires actually helped mileage a little bit. The truck also takes off better from a stop because 2nd gear isn't as low anymore..

 

I put in a 2" leveling kit. No rubbing now

 

Did you notice a fuel mileage/power loss or gain with the 33/315's? How do you calculate what your ratio would be with different size tires?

 

Truck seemed a little quicker. No loss in power. Mileage up between .5 and 1mpg freeway because of rpm drop.

 

Stock michelins turn 657 revolutions per mile. BFGs turn 601 revolutions per mile according to their website specs. I used the SC Flashpaq to adjust speedo for new tires.

 

I need to GPS mine now that I have the 33" ProComps on! I wonder what speed I'm really running at 2200 RPM's that is showing 70 mph??????-----I put a stocker Michelin up beside the 33-12.5-17's that I bought and there was not that big a difference in the height???????