when is this supposed to come out on the new GM trucks?

how much better MPG do you think it will be?

is there any other advantages to having a 6 speed other than gas mileage?

 

Supposed to be MY2009....

Check here for 2009 ordering info when it shows up. It usually shows up around June or so
http://eogld.ecomm.gm.com/dmdindex.htm

 

you should also get better acceleration, since the gears are closer in ratio, your motor will be able to stay in its power band more than with a shitty 4 speed.... i would not hesitate to get 4.11s with a 6 speed tranny....

 

Or you could stick with a 3.73 or lower rear gear combo and you would come up with a first gear equal to or better than a 4l60E first gear of 3.06 and rear end of 4.10. I can't remember the exact # for the 6l80E first gear but I believe it was in the neighborhood of 4.0X. Doing this would allow great first gear acceleration and even better highway mileage as the 6th gear is either .65 or .63 I believe. Best of both worlds!

 

The first gear ratio is 4.02 for the 6L80E. I have 3.73's and 31" tires and first gear is done by 35 mph. Second gear is good for 60. Acceleration is awesome. I can outrun my Z06 (using AWD) to about 35. Of course it gets ugly after that. For a relatively light truck like mine (4600 lbs or so) it is a screamer. The gear ratios are perfectly matched to the L92 and it never falls out of its power band. I haven’t had it tuned yet but it seems to pull harder in third and fourth gear than it does in first and second. Even with the TM turned off it seems to be held back until it reaches third gear. As for overdrive the 6L80E isn’t as great as you would imagine; the 6L80E has a sixth gear ratio of .68, only slightly better than the 4L60E’s .70 so I wouldn’t recommend any more gear than 3.73’s. First gear would be a total waste and highway cruising would be similar to the 4L60 with 4.10’s.

 

sounds like you have a pretty sweet truck. wish i had a fast own

 

It runs pretty good. Almost undriveable in the snow though. Even with AWD the low first gear, 3.73's, and light weight make it an interesting drive.

 

ya, we are getting it pretty good with snow here. glad to have all 4 wheels moving. went skiing last night. conditions were good, except i thought i dislocated my thumb after a pretty good wipeout