go to www.gmpowertrain.com. click on transmissions and you will see that using the 6 speed auto in a corvette with a 2.73 rear gear the performance drops 2% vs the 4 speed auto with a 3.15 rear gear. the 6 speed auto will only be available with the 2.73 gear. the 6 speed auto is not for performance BUT better milage and less emmisions per mile

I thnk the real reason is that the tooling isn't all received and set up to make the new 6 speed.

The transmission test eguipment is just now being built to test the completed 6 speed transmissions. My company is supporting the GM and Ford programs. Not sure of when these test machines are due to go on line.

As soon as you say supporting the GM and Ford programs it makes me think that you are talking about their joint front wheel drive program.

go to www.gmpowertrain.com. click on transmissions and you will see that using the 6 speed auto in a corvette with a 2.73 rear gear the performance drops 2% vs the 4 speed auto with a 3.15 rear gear. the 6 speed auto will only be available with the 2.73 gear. the 6 speed auto is not for performance BUT better milage and less emmisions per mile

I read that chart differently. I see it (the 6 speed auto) coming with the 2.56 gear only. The listed ratio for the Caddy 6L80E first gear is something like 4 versus the 3 for the 4L65E (current auto). Multipling the respective numbers together one gets 9.45 for the 4 speed and 10.24 for the 6 speed auto. Since gears are essentially torque multipliers there should be "higher" performance for the 6 speed auto. Having shown that why does the GM powertrain chart show lower performance for the 6 speed auto? Perhaps the gear set will be different for the Vette 6 speed than that used in the Caddy. We really don't have the whole picture yet.
Build the darn thing GM!

|UPDATED|5/1/2005 9:08:06 AM (AZT)|/UPDATED|

i should have posted 2.56 gear and that will be the only rear gear available for the 06 C-6. the gears they are showing are the corvette gears. if you look at the 0-60 times you will see that the A4 with a 3.15 gear is still quicker but the 6 speed auto with a 2.56 gear is almost as quick with better fuel milage. this is also much quicker than the 2.73 gear and a 4 speed auto which now gives the best milage. if you change the rear gear with the new A-6 you will be quicker BUT that is not what will come from the factory

|UPDATED|5/1/2005 10:17:46 AM (AZT)|/UPDATED|

there are a lot more parts to accelerate in a 6 speed auto trans vs a 4 speed auto and this slows down the acceleration just like a dual mass clutch would have taken the gear rattle out of the 6 speed manual trans corvettes BUT it would have cost .2 of a second in 0-60 times because of the xtra weight you must turn.

|UPDATED|5/1/2005 10:17:29 AM (AZT)|/UPDATED|