Stop-start tech coming to automatics

[PanterroR]

As carmakers look for innovative and low cost technologies to improve fuel economy of their cars, one such method quickly garnering acclaim is a feature known as engine stop-start tech. The system essentially shuts down the engine to save fuel when the car is sitting idly in traffic and then almost instantly kicks it back into life once the accelerator is depressed or the clutch is engaged.

So far the technology has only featured in cars equipped with conventional manual transmissions but at a conference in Berlin this week automotive parts supplier ZF has said it will have a version ready for automatic cars by 2009. ZF CEO Hans-Georg Haerter didn’t want to give any details but hinted that almost every carmaker will be offering engine stop-start tech in the near future.

Other fuel saving technologies ZF is working on include a new eight-speed automatic and improvements to vehicle drivetrain efficiency. ZF’s own testing has shown that its new eight-speed auto improves fuel consumption by up to 6% over its current six-speed auto. It might not seem like much, but with all the technologies combined cars can see reductions of up to 20%, which is a fairly nice figure considering oil prices today.


Source: Motor Authority » Stop-start tech coming to automatics

 

[EnI]

Yep, the new 7er is coming with 8-speed automatic with Start/Stop function.

 

[bmer]

Are any of the Germans considering using automatic cylinder deactivation (deactivates half of the cylinders when full engine power isn't needed) in their engines?

 

[bum-man]

It has been done before, but never really worked that well.

 

[PanterroR]

It has been done before, but never really worked that well.

True...

 

[bmer]

OK, I did some research and found out they used it in the M138 (or is it M137?) V12 engine in the MB S/CL 600. And the system Chrysler uses in their Hemi engines is based on the one Mercedes used.
I also read that Honda is using it's own version in the new 2008 Accord V6 (shuts down 2 cylinders) that uses overhead cams as opposed to MB's and Chrysler's systems that use pushrods. Maybe Germans should give this system another try because at least in theory it provides prominent consumption savings (for multicylinder engines) which are crucial when applying with the future emission standards.

 

[PanterroR]

Maybe Germans should give this system another try because at least in theory it provides prominent consumption savings (for multicylinder engines) which are crucial when applying with the future emission standards.

But buyers of multicylinder engines are, in 99% of cases, wealthy/opulent people who usually don't give a damn for fuel price or emission standards and those kind of buyers are the exact target of carmakers that do such expensive stuff like mc engines in cars that cost shitloads of money.