BMW does a 8 speed slushbox - United Bimmer Community

**celsdogg** · 02-07-2007, 11:45 PM

http://www.leftlanenews.com/2007/02/...eed-automatic/

just like lexus, BMW is developing a 8 speed auto tranny.

can someone tell me what the point of this is? i dont get it, or am missing something. all i know is i hate that lexus commercial.

What is the point of an 8 speed automatic?

witeshark · 02-07-2007, 11:49 PM

Who knows!

**cainchapman** · 02-08-2007, 12:50 AM

The Engine spends more time in the correct rev band and is more fuel-efficient. Your kick-down on acceleration is smoother too.

Better acceleration as you are closer to the power band.

e.g. You can accelerate from 18mph to 155mph in 6th gear in my car. However it's much faster if I use the other gears on the way through. It will cruise up hills in 6th, but it is more efficient to use a lower gear in this scenario too.

**celsdogg** · 02-08-2007, 07:50 AM

i understand everything about power bands power and fuel efficiency, but im sorry, still dont see the point in 8 speeds in an automatic. its unnecessary, especially for everyday driving.

**Rooz** · 02-08-2007, 09:35 AM

Quote:

Originally Posted by celsdogg

i understand everything about power bands power and fuel efficiency, but im sorry, still dont see the point in 8 speeds in an automatic. its unnecessary, especially for everyday driving.

It becomes a bragging right

**3050rpm** · 02-08-2007, 09:51 AM

I wonder if it might also have something to do with moving fuel efficiency up a smidge in order to meet CAFE standards.

drz · 02-08-2007, 03:08 PM

More gears, more time in the appropriate power band. However, I think a big part of this is a marketing thing in order to keep up with Lexus and MB.

**doughboyea** · 02-08-2007, 07:45 PM

Quote:

Originally Posted by celsdogg

i understand everything about power bands power and fuel efficiency, but im sorry, still dont see the point in 8 speeds in an automatic. its unnecessary, especially for everyday driving.

I wonder what people said when they went from a 3 speed to 4.... 4 speed to 5.... 5 speed to 6... 6 to 7.... and now.... hmm 8. Well, y the hell not? Seems the next logical number, true

?

Dough

**celsdogg** · 02-08-2007, 08:53 PM

^^^ i have heard some people describe 6 speeds as being either long legged or short legged, cant remember which. i think it was that first gear was short or something.

just more moving parts. even when they came out with the 7 speed smg for the M5 i was kinda wondering about that.

**BMW328is** · 03-09-2007, 05:54 PM

The BMW M5/M6 are beasts from a roll and accelerate on par or better than supercars in the 400-600 hp range solely because of the gear box. It greatly makes up for the lack of about 75-100 ft/lbs of torque that its competitors have with larger 5.0+ ltr engines or super/turbo charged engines.

It is in its peak power band just that much longer due to that extra gear and the advantage of a computer making shifts faster than a human can.

**mullethunter3** · 03-09-2007, 06:49 PM

Fuck it, let's make an infinity-speed auto tranny! That'll make the Lexus commercials stop... they confuse me... "So, if I buy a Lexus, I can drive in outer space???"..."Dammit! It's a runway!!!!"

**xsperf** · 03-09-2007, 08:59 PM

Quote:

Originally Posted by mullethunter3

Fuck it, let's make an infinity-speed auto tranny! That'll make the Lexus commercials stop... they confuse me... "So, if I buy a Lexus, I can drive in outer space???"..."Dammit! It's a runway!!!!"

heh, ford does, its that variable transmission thingy, it has 1 gear and it expands/contracts

but yea like rooz said, its a bragging right, so its probably marketing

**mullethunter3** · 03-09-2007, 09:04 PM

^^^how?

**xsperf** · 03-09-2007, 10:27 PM

Quote:

Originally Posted by mullethunter3

^^^how?

i dont know exactly how it works, i know they use(d) it on the ford 500, its like variable transmission or something, but since i have ridden in it, when you floor it the engine revs to 6000 then stays there(the gear expands or w/e) until you let off the gas

**xsperf** · 03-09-2007, 10:28 PM

its called the continuously variable 1-speed transmission by ford