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-   -   A concession to US emissions standards... (https://rennlist.com/forums/997-forum/600879-a-concession-to-us-emissions-standards.html)

ADias 11-09-2010 03:19 PM

A concession to US emissions standards...
 
http://images.thetruthaboutcars.com/2010/11/911c.jpg

"According to Auto Motor und Sport, the next-generation Porsche 911 (991) will have its wheelbase extended by ten centimeters compared to the current model, a concession to US emissions standards which are categorized by footprint."

And...

* stop-start technology
* electrically-controlled handbrake

zanwar 11-09-2010 06:26 PM

Perhaps the journalists at Auto Motor und Sport have been reading these forums? :)

Hella-Buggin' 11-09-2010 06:35 PM


Given the high power demands on starters to crank these high compression engines, How is that stop start "feature" going to work. I mean, it takes 20 minutes of Drive time to replenish each start of the car in current models. Must have been some serious advancements to keep the car from needing a new battery every month.

stevepow 11-09-2010 06:46 PM

tractor beam to the car ahead of you that pulls you off...

...plasma drive powers the tractor beam.

brt3 11-09-2010 06:49 PM


Originally Posted by Hella-Buggin' (Post 8043554)
Given the high power demands on starters to crank these high compression engines, How is that stop start "feature" going to work. I mean, it takes 20 minutes of Drive time to replenish each start of the car in current models. Must have been some serious advancements to keep the car from needing a new battery every month.

Ferrari is including this same "feature" on the California (which we left-coasters pronounce: CAH-LEE-FOWN-JAH)

zanwar 11-09-2010 07:05 PM

The break-even point for stop/start is around 10 seconds (if you're going to idle more than 10 seconds, it's more efficient to stop and re-start the engine). The AC and power steering also need to be electrically driven so they continue running while the car is at a standstill. The tech has been around for a long time, but the Porsche implementation will probably be the best, just like the Cayenne is the best parallel hybrid tech on the market right now.

ADias 11-09-2010 08:39 PM


Originally Posted by zanwar (Post 8043643)
The break-even point for stop/start is around 10 seconds (if you're going to idle more than 10 seconds, it's more efficient to stop and re-start the engine). The AC and power steering also need to be electrically driven so they continue running while the car is at a standstill. The tech has been around for a long time, but the Porsche implementation will probably be the best, just like the Cayenne is the best parallel hybrid tech on the market right now.

No one questions gas savings on urban driving, What Hella-Buggin' is raising is battery life and starter/alternator longevity, and rightly so.

Gj325 11-09-2010 08:55 PM

Have the start stop on my wife's new Cayenne that is the first feature we turned off the start stop sucks and that is being nice.

zanwar 11-09-2010 09:12 PM

What's the downside of the start/stop? Does the car hesitate from a standstill?

rijowysock 11-09-2010 09:14 PM

it improves MPG im sure they are doing it just so on paper the MPG is higher... **edit** i guess not :-/


Originally Posted by zanwar (Post 8044038)
What's the downside of the start/stop? Does the car hesitate from a standstill?

when i test drove cayenne the other day i didnt even notice, as soon as your foot comes off the brake it starts before your foot reaches the gas.

Alan Smithee 11-09-2010 09:27 PM


Originally Posted by ADias (Post 8042878)
"According to Auto Motor und Sport, the next-generation Porsche 911 (991) will have its wheelbase extended by ten centimeters compared to the current model, a concession to US emissions standards which are categorized by footprint."

And...

* stop-start technology
* electrically-controlled handbrake

I've said it before...the 991 has been in development a lot longer than the upcoming legislation for US emissions. And stop/start is for the EU test cycle; it does not improve EPA numbers.

Electronic handbrake, which is no surprise after seeing the interior spyphotos, is a travesty in a performance car.

Nugget 11-09-2010 09:31 PM

I didn't mind the stop/start in the Panamera loaner I had a few weeks ago. It was unsettling at first, but once I got used to it I didn't even notice.

The wheelbase increase is the only part of this that makes me sad.

Mike in CA 11-09-2010 11:21 PM


Originally Posted by zanwar (Post 8044038)
What's the downside of the start/stop? Does the car hesitate from a standstill?

My wife's Highlander Hybrid has stop/start. Maybe it's the torque of the 2 electric motors getting the vehicle going, but it's seamless and basically unnoticeable. I would hope Porsche could figure out a way to make it work as well as a Toyota.

nyca 11-09-2010 11:28 PM

Who wants a sports car that shuts itself off at a stop light? No one. It will be the first feature every owner turns off.

Macster 11-09-2010 11:32 PM


Originally Posted by zanwar (Post 8044038)
What's the downside of the start/stop? Does the car hesitate from a standstill?

My very limited experience with start/stop vehicles is there is no hesitation when the venicle is driven normally.

I never tried it but I would not be surprised if one attempted to launch (sans using the launch feature) a car with this feature active, that there might some slight delay or latency.

Depends upon how the starter is constructed. In some cases the starter is an electric motor that is part of the flywheel and there is no starter gear to engage. The starter motor has enough power to spin the engine and start the car moving along and then then engine reaches sufficient rpms that it is started and E-Gas and the engine controller see that the take off is as about as seamless as it can be.

The starter may actually be a starter and alternator in one.

The start/stop fearture has a huge payback in improved gas mileage and reduced CO2 emissions -- especially important in European markets which tax cars on their CO2 emissions -- that I would not be surprised though to find the the start/stop feature is not perfect. The drivers who put the car through its EU emissions tests and mileage tests can't turn the feature off and driveability/etc is of no importance.

Fuel consumption and CO2 emissions is all the car is graded on.

Sincerely,

Macster.


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