[6speedTi]

My question to anyone here who has the auto start/stop feature.

1) On a hot summer day with the Air Conditioning running how does the start stop feature maintain the air conditioning cool temperatures when the engine is not running?

2) The same question when running the heater on a cold winter day?

Both questions require the engine to run for the Air Conditioning compressor and the engine running to circulate the coolant through the heater core.

 

[Xcanuk]

My question to anyone here who has the auto start/stop feature.

1) On a hot summer day with the Air Conditioning running how does the start stop feature maintain the air conditioning cool temperatures when the engine is not running?

2) The same question when running the heater on a cold winter day?

Both questions require the engine to run for the Air Conditioning compressor and the engine running to circulate the coolant through the heater core.

When there are any excess demand, A/C and I assume heat, it does not work. If the battery is low, it won't either, which is the main reason for mine not working. There is a blurb on it in the manual.

 

[Acrtryx]

There are a long list of preconditions that have to be met for the engine to auto stop. Low heat and AC load are one of them. See page 164 in the owners manual.

 

[MyEvilTwin]

Just asking, did your dealer verbally say it was turned off, or have you never seen it work?. In the same logic, can you turn it on ? (Is the A/S switch lit)
Mine did not work at pick up at the dealer, worked for 3 months after an update, haven't seen it since last fall.
You are the first to mention a dealer "off" setting vs just plain not working.

I can't remember if the salesman used the term "disabled it" or "turned off". It was one or the other. Every other feature works except for that one.

 

[MyEvilTwin]

There is no “turned off” option so your dealer must have misstated. By regulation the start/stop must rengage each time the vehicle is restarted.

In regards to actual fuel savings, yes they exists and are not insignificant. You can spend 5 min googling the studies. Evidence is pretty cut and dry. Start stop saves fuel after about 7 seconds of not idling and saves 4-9% fuel overall depending on drive cycles. Probably even better now as that is from a 21 year old study.

Start stop does not engage unless engine is at temp and not under load. This means these are not “cold”/“dry” starts. The wear put on your engine in a start/stop condition is not comparable to normal startup.

Starters are designed and validated with start/stop in mind. If you want to spend 4-9% more on fuel over 300k+ miles to extend the life of a $200 starter from 300k miles to 1M miles then feel free but that math ain’t mathing right. The fuel savings will pay for that replacement starter that is unlikely to fail anyway 20x over.

I'm not sure what my dealership did but the salesman stated they did something to make sure it doesn't work. What they did I don't know and I'm not sure what the laws about it are up here in Canada. I like the feature on my wife's VW. I just don't use my ZR2 enough to notice a difference.

 

[NortheastWanderer]

Im not sure about your specific driving habits, but you may actually notice an increase in fuel economy. I did some experiments with my truck and found i was getting noticeably better fuel economy with it off 100% of the time

 

[sleepngbear]

How was it turned off when you purchased it?
It automatically turns on again when you restart the vehicle........at least in the USA.

My guess, with this precision instrument.

 

[MyEvilTwin]

Im not sure about your specific driving habits, but you may actually notice an increase in fuel economy. I did some experiments with my truck and found i was getting noticeably better fuel economy with it off 100% of the time

You would be an anomaly and a case study in and by itself. Every study I have read shows increased fuel economy by using the stop start feature.

 

[Xcanuk]

I just don't use my ZR2 enough to notice a difference.

I think "that" is the issue. If you do not use the truck enough, it will not work. I think the truck has to be a daily driver and trips averaging over 20-30 minutes.
Is the A/S switch lit when you start the truck ?

From experience, I put a big doubt on what sales reps say, especially with their connection to mechanical stuff. If what they said was true, my rear seats were supposed to fold.
Now.. if the service rep stated they disconnected it, that would be another scenario, but I don't see any dealer modifying a GM feature.

 

[JT58.Bronco66]

So much debate on the auto stop feature. I personally like it. To simply put it I use it when I am the first or nearly the first at a light when the light is 5 minutes long. Mine times out actually the lights are so darn long where I live and the truck starts up before the light changes anyway. I just push the button to turn it off when I am at a short light, or I know it's about to change. I also turn it off when I am parking and will stop the truck, back up, etc. so it won't shut off. The start/stop does not always work either....if the battery is low due to the truck sitting for a day or two it won't work until the battery charges up. So I use it but practically when I want to. The button is there to turn it off, I don't understand all the hate.

 

[MyEvilTwin]

I think "that" is the issue. If you do not use the truck enough, it will not work. I think the truck has to be a daily driver and trips averaging over 20-30 minutes.
Is the A/S switch lit when you start the truck ?

From experience, I put a big doubt on what sales reps say, especially with their connection to mechanical stuff. If what they said was true, my rear seats were supposed to fold.
Now.. if the service rep stated they disconnected it, that would be another scenario, but I don't see any dealer modifying a GM feature.

I understand what you are saying but every ZR2 I tested drove had the feature work. It's not like I use the truck for a 2 minute drive every other day and that's it. I can spend 45 minutes driving across my city and it never comes on. It's just the truck will sit in the driveway for 2 or 3 weeks before it gets used again, but when it does get used on that day or weekend it should meat every criteria for the feature to work. I'm sure if it was me not using it enough or properly the salesman would not have said they shut it off/disabled it. Why he said that and specifically pointed it out I don't know. The switch itself is dead. No light or anything.

 

[Xcanuk]

I can spend 45 minutes driving across my city and it never comes on. It's just the truck will sit in the driveway for 2 or 3 weeks before it gets used again.
The switch itself is dead. No light or anything.

OK, gotcha, if the light is "off" at start up, then I would assume they did something, quite sure there are others who would like to know what, since most kits are only coming out now that don't cause side effects. Personally, I'd like to see mine work.
That being said, mostly last year, (using the truck every second, third day) it would start to work after driving for 30 minutes and would work for the balance of the day, then it took closer to an hour of driving. Now that I'm down to driving once a week if I'm lucky, I haven't seen it, but my light remains on, so technically its active. I just need a good road trip.

 

[ColoranyonKidd]

My 24 ZR2 has the feature turned off and it was turned off when I purchased it new. Having said that it's active on the wife's car and works fine. The comments in this post saying it will starve an engine are hilarious, have zero data to back it up and usually come from the same people that say an aftermarket cold air intake adds 10hp on their butt dyno.
If the oil film is gone after the 30 seconds or minute you are sitting at a stop light you are using the wrong oil. I've spent over 30 years making a living as a mechanic and I have yet to see 1 engine where I can say that the auto stop start technology caused an engine failure.

"If the oil film is gone after the 30 seconds or minute you are sitting at a stop light you are using the wrong oil."

Well, let's just clarify one indisputable fact: The engine bearings depend on oil PRESSURE to live. There has to be a hydrostatic oil layer present (oil at PRESSURE, not JUST an oil film) to adequately protect the bearings and crankshaft journals from wear, or worst case, catastrophic failure. So, just using that bit of knowledge, this feature cannot be good for your engine OR transmission. Is it going to cause of any engine/transmission failures? Most probably not. But why not just say what this start/stop feature actually IS: and that is an attempt to help manufacturers meet the corporate average fuel economy (CAFE) numbers. And maybe some miniscule savings in terms of emissions. Why is there so much controversy on this? Mainly because most folks HATE this feature on their vehicles. None of the folks that I know like it. None. The fact that there are companies out there selling devices to disable this feature is a testament to this fact. Again, where are the actual tests/studies that actually quantify the ONLY possible benefit to the owners of vehicles so equipped--and that is a very small savings in fuel costs? I have not seen ANY published data on this. Must be a big corporate secret. And THAT fuel savings, if any, depends on the actual usage of the vehicle. OK, subject has been adequately beaten to death. As for me personally, I'm SO GLAD my 2022 Colorado V6 does NOT have this "feature" to contend with!

 

[FireNative2]

Auto start/stop is not for the vehicle owner it is for the vehicle manufacturer. You save 0.24 to 0.5 mpg per tank and 1mpg with extreme stop and go traffic which does nothing for you but the pollution it saves per hundred thousand 3rd gens they sell each year gets them eco points from the government. So they don't care if you have to buy starts more, or the extra wear and tear on your turbo and motor will make it need maintenance/repair/replacing sooner because they also hope to sell you the parts and the labor since all of this should happen right out of the 3yr warranty

 

[BigMick23]

Where I live I need to enter a busy 65 MPH highway from a dead stop with no acceleration lane........
On my Silverado, many times I'm sitting there waiting to go with busy traffic, finally an opening, go to stomp on the gas and the engine quits then starts again immediately.
Not only unnerving but that just cannot be good for an engine, I don't care what anyone says.

It's a total joke.......give owners the option to turn it off permanently!
I purchased the ASS disabler for my new 2026 ZR2.....I don't want to deal with it.

 

[sleepngbear]

I personally hate it, and the first thing I do when I get in any vehicle that has it is look for that button to shut it off. There’s something I find extremely off-putting about the car having to do something else before it actually goes when I step on the gas. My wife on the other hand doesn’t mind it and kept it on in our last car that had it. Used to drive me nuts.

 

[gherbert]

Been reading through this thread, mainly for amusement purposes. Thank the Lord my 2022 Colorado V6 does NOT have this feature. I realize most think this feature really does no harm, but maybe just try thinking logically about this... "dry" starts are the enemy of any engine, and this fact has been documented by lab (ppm lead in the oil) testing/analysis. Lead in the samples...the thing is, it can only come from ONE source in an engine--and that is the main and rod bearings. Also think about the auto transmission--start/stop simply cannot be good for the clutches, as it takes a bit for the hydraulic pump to build sufficient "clamping" pressure on the clutch packs. With all the trans troubles we read about here and on other forums, do we really need this added to the mix as well? Lastly, in terms of ACTUAL fuel saved, can anyone point me towards a study where the fuel saving is actually QUANTIFIED, this for an average motorist in combined city/freeway driving? This start/stop feature CANNOT add anything to engine longevity, so the savings, IF ANY, have to be in fuel, and possibly emissions. I realize that is the stated goal. I simply would like to know what that number actually IS for the "average" motorist.

What are you talking about a "Dry Start"?
If you are referring to Oil?
How much Oil do you think can drain back in 2 minutes?

There is NO Dry if you are referring to Oil

 

[MyEvilTwin]

"If the oil film is gone after the 30 seconds or minute you are sitting at a stop light you are using the wrong oil."

Well, let's just clarify one indisputable fact: The engine bearings depend on oil PRESSURE to live. There has to be a hydrostatic oil layer present (oil at PRESSURE, not JUST an oil film) to adequately protect the bearings and crankshaft journals from wear, or worst case, catastrophic failure. So, just using that bit of knowledge, this feature cannot be good for your engine OR transmission. Is it going to cause of any engine/transmission failures? Most probably not. But why not just say what this start/stop feature actually IS: and that is an attempt to help manufacturers meet the corporate average fuel economy (CAFE) numbers. And maybe some miniscule savings in terms of emissions. Why is there so much controversy on this? Mainly because most folks HATE this feature on their vehicles. None of the folks that I know like it. None. The fact that there are companies out there selling devices to disable this feature is a testament to this fact. Again, where are the actual tests/studies that actually quantify the ONLY possible benefit to the owners of vehicles so equipped--and that is a very small savings in fuel costs? I have not seen ANY published data on this. Must be a big corporate secret. And THAT fuel savings, if any, depends on the actual usage of the vehicle. OK, subject has been adequately beaten to death. As for me personally, I'm SO GLAD my 2022 Colorado V6 does NOT have this "feature" to contend with!

Yes the engine oil bearings depend on pressure to live..but only only in an environment where the engine is under load. The oil film that is present at these repeated start ups should be more than enough to maintain engine life. Since the engine and the oil are both at operating temperature the oil pressure will build up very quickly. Once the engine is placed under a load..as in you are now driving...there must be both a minimum amount of oil pressure and a minimum volume of oil. I'm astounded still to find so many drivers think this is a dry start every time the engine shuts off at a stop. Its not and your engine was designed for this.
Do manufactures use this to meet CAFE numbers? They would be foolish not to. As the SAE points out, under the right circumstances with the right vehicle they can see fuel economy increases of as much as around 25%. That's huge. Does it help with emissions? I cant see it.
Is it controversial? Sure and so was the seat belt. The majority of this comes from ignorance. Someone watched a video once but some random person that claims they know it all, probably Scotty Kilmer, and that its bad for engines and like typical internet fashion it spread without people doing their own research.
Natural Resources Canada has previously published a report stating the technology reduces fuel consumption from 4 to 10%. Depending on your driving habits etc you could save a few thousand dollars over a 10 year period. Edmunds has published data showing fuel savings averaging around 10% on 3 different test vehicles. AAA published their findings showing gains of 7%. Some Subarus acting record your fuel savings when you use the technology. The data isnt hard to find. Using my houses personal commuter we save approx 4lt of fuel per week. Is this huge? No it works out to a savings of just over $5 per week. But then again the commute is not long at 20 minutes each way and it still adds up to over $260 in savings per year.

 

[walleyshere2]

I wish that my auto-stop would stop working.. i manually turn it off every time i get in my truck. the service manager at my dealership told me that because i drive short distances to work (15mins) it could be harming my battery by not letting it get back to full charge by the time i park. my battery was replaced after 6000km (3700miles) and i believe it was faulty from the factory, but the dealer seemed to say that they see this often and battery condition appears to be related to auto-stop/start in their opinion.
I am afraid to try any "hacks" i have seen to disable it because i don't want to deal with potential side effects.

 

[C74fun]

On balance, I like Auto Stop. So, not happy to see it stop working a couple weeks ago. Took my ’23 TB into dealership, and after an hour or so the tech came up with the culprit: a voltage sensor associated with the battery had failed. So, ordered the part. This loss appears to affect no other aspect of drivability.
I did ask his opinion of Auto Stop. He said GM is adamant about there being no problem with repeated "dry starts”. He did say that he has turned this function off in his vehicle, b/c he is convinced it reduces starter longevity - both concerns shared by a host of forum posters.
A skeptic might conclude that GM has timed the long term effects of the Auto Stop (engine wear/failed starter), to kick in a year or so after the warranties expire.
Going forward, I may try to develop practice of engaging it, when approaching a stop that may leave the engine idling for a prolonged interval ( > 30-40 seconds).

It's not GM that wants that junk, including AFM. It's the government tree huggers costing auto makers and mostly us millions to meet EPA requirements .