2016 Cayenne auto start/stop: ARRRRRRRGH!!!!
12-29-2015, 04:24 PM
#17
Rennlist Member
I too have a 2016 Cayenne since July. I also have a 2013 MB C Class with auto stop start. While we love the Cayenne, the *** is annoying and dangerous. Firstly, it is programmed to shut down at 4Km/hr. as per the Owner's Manual. If you are slowing gently to a stop you lose the power steering which isn't good if you are trying to slightly correct the vehicle position.
As for the surging, that sounds like either operator error (hitting the gas too hard before the engine restarts, resulting in a surge) or system error, in which case Porsche needs to fix it or else they'll be on the hook for killing someone!
All that said, press the Sport button. With Sport mode activated, *** is deactivated.
12-29-2015, 04:50 PM
#18
Racer
At 2 to 3 km/hr you cannot move the steering wheel enough to restart the engine. If I could muscle it my wife certainly cannot. This is just bad design, it should not shut down until a complete stop.
There is no driver error, the surging occurs before my foot ever gets to the gas pedal. I suspect the service manager is right, it's the AC coming on. Again, bad programming.
There is never any shut down at speeds above 4km/hr.
Of course putting it in sport will negate the Auto SS, but so will turning it off.
Love the vehicle, but expected better programming from Porsche. I have a 2013 C2S and a 1989 964, so I really appreciate their engineering, but they aren't perfect. They really should reprogram their Auto SS. But I don't expect they will.
There is no driver error, the surging occurs before my foot ever gets to the gas pedal. I suspect the service manager is right, it's the AC coming on. Again, bad programming.
There is never any shut down at speeds above 4km/hr.
Of course putting it in sport will negate the Auto SS, but so will turning it off.
Love the vehicle, but expected better programming from Porsche. I have a 2013 C2S and a 1989 964, so I really appreciate their engineering, but they aren't perfect. They really should reprogram their Auto SS. But I don't expect they will.
12-29-2015, 09:39 PM
#19
Rennlist Member
I too have a 2016 Cayenne since July. I also have a 2013 MB C Class with auto stop start. While we love the Cayenne, the *** is annoying and dangerous. Firstly, it is programmed to shut down at 4Km/hr. as per the Owner's Manual. If you are slowing gently to a stop you lose the power steering which isn't good if you are trying to slightly correct the vehicle position. My MB doesn't shut off until a complete stop. The worst thing is that on three occasions when I took my foot off the brake the car restarted and lunged forward. I needed to be very quick back on the brake to slow it down. If a pedestrian were in front of the car it would have been dangerous with someone not so quick back on the brake. I'm guessing it has to do with the programming where the engine restarts under certain conditions and it just happened to occur as I took my foot off the pedal. It happened to my wife also and makes her nervous. This never happens with the Mercedes system. I have instructed my wife to always shut it off as a safety measure. I will get it to the dealer but I am sure they cannot adjust it. We love the vehicle having previously owned a MB ML for 8 years, but Porsche needs to do something about their *** programming.
01-15-2016, 07:04 PM
#23
Advanced
Join Date: Jun 2015
Location: SF Bay Area
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
I can see why the A-S-S thing may be annoying.
By the time you realize that you forgot to deactivate it, your engine is likely due to restart BELOW operating temperature. And that's not good, unless you're a Porsche mechanic in dire need of customers with broken engines.
Better not be forgetful.
I can also see why too much A-S-S "sits" alongside the Kardashians on the annoyance scale for the V6. As an inherently unbalanced engine, the start ups are noticeable and reliably disturbing.
However, my 2012 CTT poses a different problem. Due to the characteristic dissonance of the V8 exhaust system (cross-plane crankshaft), it is actually annoying to have the engine on idle.
So while I sympathise with everyone who doesn't like the A-S-S function, I actually activate it for long red lights and similar situations.
I mean that I actually turn the button on and off three or four times on a typical commute.
I guess a mild OCD is a good recipe for mitigating forgetfulness.
By the time you realize that you forgot to deactivate it, your engine is likely due to restart BELOW operating temperature. And that's not good, unless you're a Porsche mechanic in dire need of customers with broken engines.
Better not be forgetful.
I can also see why too much A-S-S "sits" alongside the Kardashians on the annoyance scale for the V6. As an inherently unbalanced engine, the start ups are noticeable and reliably disturbing.
However, my 2012 CTT poses a different problem. Due to the characteristic dissonance of the V8 exhaust system (cross-plane crankshaft), it is actually annoying to have the engine on idle.
So while I sympathise with everyone who doesn't like the A-S-S function, I actually activate it for long red lights and similar situations.
I mean that I actually turn the button on and off three or four times on a typical commute.
I guess a mild OCD is a good recipe for mitigating forgetfulness.
Last edited by Rennaissance; 01-16-2016 at 04:29 AM.
01-15-2016, 07:40 PM
#24
Rennlist Member
Maybe I'm one of the few, but I don't mind auto stop start. To me, performance encompasses not only power, but handling and efficiency as well.
There are times when I'm using the power and handling, but other times when I'm just stuck in the flow of traffic when I'm fine with the car optimizing efficiency by shutting down at lights. It's surprising how quiet things are when the engine shuts off.
Anyway, when I'm in the mood for sportier driving, it's just one push of the sport button, or I take the Carrera.
There are times when I'm using the power and handling, but other times when I'm just stuck in the flow of traffic when I'm fine with the car optimizing efficiency by shutting down at lights. It's surprising how quiet things are when the engine shuts off.
Anyway, when I'm in the mood for sportier driving, it's just one push of the sport button, or I take the Carrera.
01-15-2016, 07:59 PM
#25
Rennlist Member
Interesting thread. It may be one of {many} reasons why I won't upgrade from my 2012 CTT, since it does indeed remember my setting (post #3). So I leave *** off & it stays off permanently. Then when I am approaching a light that I KNOW will be a long one, I pop it back on {just for that light}. This approach works for me, since it is that realization that keys me to think - press the *** Button!! & shut the motor down.
Oh, & no, I never experienced any shutdown prior to complete stop. Nor any steering issues.
So I guess these early 958's (w/ *** Memory) made it under the EPA mandate that *** stay on.
{can't help it,... just too much acronym fun}
=S
Oh, & no, I never experienced any shutdown prior to complete stop. Nor any steering issues.
So I guess these early 958's (w/ *** Memory) made it under the EPA mandate that *** stay on.
{can't help it,... just too much acronym fun}
=S
01-15-2016, 08:56 PM
#26
Advanced
Join Date: Jun 2015
Location: SF Bay Area
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
From the user comfort perspective, A-S-S may or may not make sense. Depends on your preferences.
From the fuel economy perspective, the effects are negligible. The restart itself is inefficient. The engine needs to be off for at least 16 seconds just to save the fuel that the subsequent startup will consume. Time your typical traffic stop interval - I doubt it lasts 16 seconds.
Now from the longevity point of view, the effects are also negligible IMHO. The auto start is far more gentle than a normal startup. The one thing to watch out for are auto starts at below normal operating temperature.
From the fuel economy perspective, the effects are negligible. The restart itself is inefficient. The engine needs to be off for at least 16 seconds just to save the fuel that the subsequent startup will consume. Time your typical traffic stop interval - I doubt it lasts 16 seconds.
Now from the longevity point of view, the effects are also negligible IMHO. The auto start is far more gentle than a normal startup. The one thing to watch out for are auto starts at below normal operating temperature.
01-15-2016, 08:59 PM
#27
Rennlist Member
I've got a **** system in my MB E550 Cab. It is a complete waste of engineering effort. I try to remember to turn it off, but usually forget. If the system is active, and seat heaters are on, the car restarts at the same traffic light. One thing they did really well, incredibly smooth restart with the V8.
We just keep allowing the EPA/CARB to tighten regulations and the automakers have to make more desperate, expensive and marginal solutions.
We just keep allowing the EPA/CARB to tighten regulations and the automakers have to make more desperate, expensive and marginal solutions.
01-16-2016, 01:32 AM
#29
Rennlist Member
I've also experienced where the A-S-S will not execute even when water temp is up to normal, but oil temp is not yet there.
I only tested that in the early months of ownership. Ever since then, I keep it off, and only turn on when I am approaching a light that I know is long. I'm sure most lights are not long enough,... but feel I might as well conserve some gas (at the expense of my starter).
01-16-2016, 07:47 AM
#30
Advanced
Join Date: Jun 2015
Location: SF Bay Area
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
I don't know exactly how long the large V8 engine needs to warm up, but I would think that at 3 minutes past cold start the pistons are still at a wide temperature difference from the heads and the block.
The oil temperature tends to be around ~140'F when the auto stop kicks in for the first time.
My oil temperature goes to normal (208'F) after about 10 minutes of city driving. That's the oil temperature. Not sure if cylinders & pistons are warm enough by then.
I only tested that in the early months of ownership. Ever since then, I keep it off, and only turn on when I am approaching a light that I know is long. I'm sure most lights are not long enough,... but feel I might as well conserve some gas (at the expense of my starter).
An extreme example is the "California stop" which saves a lot of gas compared to a full stop. Especially with the *** engaged.
Let alone brakes or tyres...