tiag335

Does anyone know what the max torque rating on the new 8-speed auto is?

questionlp

I know that a form of the 8-speed Tiptronic is used on the 2011 Q7 3.0TDI, which is rated at about 400 ft-lb of torque. A version of the same transmission is also used in the 2011 A8, though I don't know if it will be used with the higher output engine that will be coming out later.

The A6 family, which will see a revamp for the 2012 model year, still has the carry over 6-speed Tiptronic. I wouldn't be surprised if they didn't switch it out for the 8-speed with the new generation.

tiag335

You are quite right in pointing out that there are many versions of the ZF 8HP transmission. The one fitted in the Rolls Royce Ghost can handle over 700 ft-lb. But I'm specifically interested in the variant used by Audi in conjunction with the 2.0TFSI engine.

fred44nl

may be this helps:
(from http://en.wikipedia.org/wiki/ZF_8HP_transmission)

List of ZF 8HP variants

name max. gasoline torque (N·m) max. diesel torque (N·m) example
8HP30 300 300
8HP45 450 500
8HP70 700 700 BMW 7 Series (F01)
8HP90 900 1000 Rolls-Royce Ghost[13]

ItsDubC

I don't know much about the new 8-speed but on the older 6-speed, the torque converter seems to be the limiting factor and not the transmission itself. Transmission load ratings seem to be much easier to find than load ratings for torque converters unfortunately.

tiag335

Thanks for the info, but which one is the variant used in the A5?

questionlp

I'm going to have to guess the 8HP45, since 265 ft-lb is approximately 360 newton meters.