8 speed BMW auto v 6 speed BMW Auto DS (Sports mode)

[Welshbeef]

When in DS mode in the 6 speed auto it will not chage up to 6th gear 5th being the highest.

What is the highest gear the 8 speeder will go up to in sports mode?

Note reason it holds 5th in the 6 speeder is top speed is limited to 155mph as such it achieves that speed in 5th gear so no "need" for 6th.

[Ozzie Osmond]

Welshbeef said:

Note reason it holds 5th in the 6 speeder is top speed is limited to 155mph as such it achieves that speed in 5th gear so no "need" for 6th.

I don't think that's the reason. Top gear (6th) is generally just an overdrive for economy and any acceleration in that gear would be far from "sporty" - hence locked out in sport mode.

Don't know how many gears would be in play with the 8-speed in sport but would be surprised if it's all 8 of them. The extra gears are for both performance and economy, enabling the engine to be at its optimum rpm for more of the time. Since in "sport" the revs are held to a higher level in each gear the top ratio becomes completely superfluous.

The key thing with either transmission is that unlike a manual gearbox they are not stand-alone units. That is, the engine and gearbox are not separate from each other. The engine and gearbox are constantly talking to each other and operate as a single system. Amongst other things this allows the use of a compact auto transmission with a big engine. Engine torque during shifts is carefully managed by the computer so the engine doesn't rip the transmission to shreds.

[Zod]

I can't get the 8 speed box into 8th using the manual mode, just 7th.

[Welshbeef]

Does the 8 speeder change gear quicker than the 6 speeder?


I can DS(M) change to any of the 6 gears.

[Maxus]

In D/S my 8 speed auto goes up to 7th at UK motorway speeds. Not sure if it will eventually go into 8th. You can go to 8th using manual +/- control.