I almost always drive in normal mode with the auto start/stop button engaged on the highway. The coasting feature is brilliant. It is not at all obtrusive to the driving experience and I can easily get 350 to 380 highway miles on a tank of gas with auto start/stop engaged.

 

Lex - We do a lot of long trips, so I’m interested in better mileage.

In a MT car, how does *** work to improve mileage cruising in 7th? Just trying to work out the mechanism here. Is it via the overall temperature setting? I have noticed steady state temp in Sport is lower than non-Sport (about 194° vs 217°) running continuously.

 

I got the APR tune for my 991.2 and it turns off *** by default. I rarely drive on the freeway or in town but will turn it on sometimes to take advantage of the coast feature.

 

Did you hear that Cobb? And if you added that feature to your next update along with one to remember what mode the car was in when last turned off (e.g., Sport mode) you would have a reason for others to consider your tune more than others!

 

As stated above, in an MT car, *** does nothing on the highway when in gear.

The temp change is unrelated to ***. The lower coolant temp in Sport increases engine power slightly and helps to keep oil temp under control.

 

​​​​​​​Couldn't agree more. Its garbage like this that causes the base price of the 911 to jump 20% from model to model. At the end of the day its sort of lazy engineering to just make a more complicated rat trap and pass the costs along to the consumer.

 

Makes perfect sense to skimp gas after spending 125k on transportation. Makes me feel all eco conscious inside.

 

I'm not sure how it works. I suspect it's something in the DME. Certainly not mechanical, like the PDK cars. I routinely do this drive (La Crosse WI back to the Chicago area) and the best mpgs are always achieved with auto stop start active. I'll play with it and check it again this Spring. Regardless, antidotal or not, it's amazing what these cars can do when just cruising alone in the right lane.

 

I didn't even know I have the cruise part of this because I never run in comfort, but i've only had the car for two years.
My Macan does and another little tip is if you see it not cruising when you let off the gas (manual shift mode) you can pull for an imaginary 8th geat to kick cruise on.

 

This is how I do it, this method also deactivates smart charging ensuring your battery continually gets fully charged just like in the old days, everything other than smart charging and auto stop start works as it should. Did the same on my Merc shown in the vid over a year ago, battery on that car is dated 3811 and still holds a full 12.8 volt charge. The Merc has been in my ownership since early 2015, stop/start has never been used by me on that car.

 

just turn it off and the light on the button will stay lit and the car will not auto stop

 

There are a lot of ways to accomplish the same thing, but only 2 that I know of that do it properly.
This video shows one way to do it "improperly". I say that because I personally would not like to have a warning triangle flash on my
instrument cluster every time I start my car. It also leaves two hanging cables in the engine bay that would need more than tape to keep moisture from entering..

The T9 design module is a great solution. It connects behind the shifter area under the control pod and just plugs in. Once installed, you never have to deal with start/stop and no warning lights.
It also allows you to instantly turn it back on with a simple push of a button so, you maintain functionality and accomplish complete deactivation if you so choose. I have it and from the day it was
installed I never once turned it back on. It is permanently disabled with no warning lights or loose cables.

Second way is by tuning. I have read that certain tuners can now re code the auto start/stop to remain off. Dont know if it can be enabled by pushing the button or not, but this is a better solution
than disconnecting the battery cable and getting warning lights and risk damaging the terminals.

 

Quote:

There are a lot of ways to accomplish the same thing, but only 2 that I know of that do it properly.

The warning triangle just informs you that auto stop/start has been deactivated, that`s it, one flick of the bottom stalk gets rid of it, the added benefit of disconnecting the sensor is smart charging is also deactivated which as already stated alters the charging regime from intermittent to continuous which ensures a fully charged battery even on mainly short journey`s.

These two systems stop/start and smart charging marginally improve MPG, I would not have bought a Porsche if I was overly concerned on it`s fuel usage.
Smart charging increases the charge voltage on overrun which slows the car down, without smart charge in play the Porsche will coast for long distances as the ECU places the PDK in neutral therefore there is little fuel gain from this complex system but it`s one more unnecessary item that can go wrong. As far as damp is concerned, it`s under cover and in a dry area.

 

Robuk: The warning triangle opens as a large warning and hitting the stalk button minimizes it to the bottom of the display. As far as I know, that is where it will remain forever. The small warning triangle is there for life and you cannot remove it from the display. To me it is annoying and will ultimately burn in the screen. Its also a topic for discussion at every dealer service. Not for me.

I have no idea about smart charging, but my battery starts the car and runs my stereo so I am ok with its current functionality

 

Get a piece of triangular black vinyl to cover it up, or electrical tape for the elcheapo fix.