Auto Stop/Start

[kpanza]

Hey guys, just wondering if you could chime in on how LONG your truck will stay in the "Auto Stop" condition (for those of you who don't disable it every time you get in truck).  I just read some GM marketing blurb on the system, and they are claiming it can stay in the Off condition for up to two minutes??  The longest I have ever gotten mine to stay off is like 35 seconds, and often is less?  I am used to the technology, as our 2018 Pacifica has it, and it can stay off for 1-2 minutes easy if the conditions are right?  Wondering if I need to have dealer look at the auxiliary battery if mine isn't working right?  My driving is 80% city, stop and go, so it would obviously have more of an effect on my MPG if it was shutting down for longer at lights?  Truck is a '20 SLT 6.2 with max tow, am averaging 12.9mpg over first 1850 miles...so far is worse than my '10 Silverado with 6.2 and max tow (and it had 3.73s!) was. 

[2016 Sierra Owner]

On my 20 if you come to a stop with the brake firmly pressed the engine will stop. If I let up off the brake just slightly (truck does not move) then engine will crank up. Also if I come to a stop with the A/C on the engine will shut off but, once the air starts getting warm. It will start up again. I've never really timed it to see how long it will stay off though. I will say that my 16 5.3 2wd 6 speed got the same fuel mileage as my 20 5.3 4x4 10 speed. I average around 16MPG mostly all city driving as I live about 7 miles from work.

 

 

[wahoowad]

Hmmm. My 2019 Trail Boss seems to have stopped with the auto stop/start but I assumed it was due to me running the A/C with the summer heat. I wonder if mine is defective? It hasn't done the stop for a couple months.

[redwngr]

There is a list of things that will make it restart (or not shut off).

 

 

Auto Stops may not occur and/or Auto Starts may occur because:
. The climate control settings require the engine to be running to cool or heat the vehicle interior.
. The vehicle battery charge is low.
. The vehicle battery has recently been disconnected.
. Minimum vehicle speed has not been reached since the last Auto Stop.
. The accelerator pedal is pressed.
. The engine or transmission is not at the required operating temperature.
. The outside temperature is not in the required operating range.
. The vehicle is in any gear other than D (Drive).
. Tow/Haul Mode or other driver modes have been selected.
. The vehicle is on a steep hill or grade.
. The driver door has been opened or the driver seat belt has been unbuckled.
. The hood has been opened.
. The Auto Stop has reached the maximum allowed time.

[aliveguy5]

Spoiler

 

When I have the AC off I've had mine shut off for around 2 minutes. With the AC on it's certainly not as long, but we've also had a hot summer. As far as MPG's are concerned with your 6.2. Once my motor started to get around 5,000 on the odometer I noticed a very steep increase in the MPG's, and the engine is way more responsive. I know it isn't talked about much but I think the 6.2's need a few thousand miles to truly break in. Also I just towed a 7,000lb travel trailer and at 65MPH my truck was averaging between 10-12MPG on flat land in tow/haul mode for a reference. Your mileage should improve in time.