Cadillac Owners Forum banner
  • BEWARE OF SCAMMERS. Anyone trying to get your money should be checked out BEFORE you send anything anywhere.

Thoughts on Automatic Engine Stop/Start?

18K views 48 replies 27 participants last post by  scooter107  
#1 ·
I purchased a 2016 new ATS 2.0T AWD Lux in late January 2017. I love the car but wanted to get others' thoughts on the Auto Engine Stop/Start feature. The system functions well, shutting off the engine at traffic lights, etc. and immediately restarting upon brake release. Being an "old school" guy, it seems like frequently shutting off the engine only to restart it again in just a few seconds might produce unnecessary wear. I understand that the purpose of the system is to save fuel, but is the saving of the small amount of fuel spent idling for generally less than a half minute worth any extra wear on the systems? My gut tells me it is better to keep the engine running so I have been disabling the auto function to prevent the engine from shutting down unless I command it to do so. Of course, disabling the system is only good for one ignition cycle so I must remember to do it each time I get into the car, but that has become my habit now so it is not a big deal. I would appreciate any thoughts on the wisdom of using or not using the system.
 
#2 ·
I dislike stop/start and although these systems are supposed to have an upgraded starter rated for this service I agree with you that there is a possibility of additional engine wear from the stop/start as oil pressure has to come up at every start. I am glad my 2014 doesn't have it and how it is implemented will impact whether I buy another ATS (or similar) in a couple of years. I had a midsize Chevrolet rental while spending a week in Florida last summer and the only way to disable its stop/start system was to leave the automatic transmission in manual mode. In hot Florida weather it would sometimes cycle a couple of times at lights when the HVAC system commanded the compressor back on. As a driver I know whether I am going to be stopped for some time (waiting on a train) or if I am at a four way stop or a rapidly cycling traffic signal and I prefer to make my own engine shut off decision.

Wait until these cars get a few thousand miles of poor maintenance and they will become instant traffic jams as they automatically shut off and then won't restart.
 
#3 ·
That sort of knee-jerk system would drive me batshit.

It probably came about due to the car manufacturers trying anything to meet the stupid EPA mandates for C A F E.
 
#5 ·
There were a lot of these discussions when the 2016s first came out, in case you want a lot more opinions.

The car starter, extra battery, etc, is beefed up to be able to handle that. I leave it on for routes where quick starts are useless or
someone else is in the car and I have to drive weakly. When it's too hot/cold out, it either stays on or restarts before a green light.
I lease the car, so wear and tear does not matter to me. I don't feel like I am saving much gas. You do have to address lights/stops
differently. Once it's off at a light, you don't want to creep up and have it start up. Stay still and let it stay off.

I think do whatever you like to do. All future cars may have start/stop, unless a possibly relaxed CAFE will make it worth doing away with.
 
#7 ·
I have had several loaner Cadillacs with the auto stop/start and I have to say I'm absolutely not a fan of it. It's too abrupt and noticeable and I hate that it even sounds like you're restarting your car every time you take your foot off the brake. If this is going to be the way of the future in new Cadillacs, at least give us the option to disable it. On the ATS and CT6, you can turn the feature off every time you get in the car, but on the new XT5, no such toggle exists.

I agree that the cons seem to outweigh the pros. Even though the components were designed with the auto stop/start system in mind and I'm sure are rated to last longer than "older" components, it seems like the wear produced by stopping your car every 30 seconds (think cities with lots of red lights/stops) isn't worth the pennies of fuel saved. I also hate that if you inch your car up in traffic, your car restarts again, going back and forth between cycles at one red light!
 
  • Like
Reactions: RedCadi
#8 ·
^^^ it's the way of ALL new cars, not just Cadillacs. Cars in other parts of the world have had start/stop much longer than we have (so I have read anyway). All manufacturers are doing it so get used to it. They have to meet EPA regulations.
Here is the the thing, it's one of those features that you have to get used to and learn how to work with it. So on a loaner, or a test drive won't cut it. Of course you're not gonna like it. It absolutely took getting used to after buying my 2016 3.6, but I have grown to not mind it, infact I really like the smoothness and quietness when sitting at a long light, and burning no gas is obviously a benefit as well. I doubt engine wear is an issue, obviously the engineers aren't complete idiots lol. They say the beefed up starters are good for 1 million plus starts. Starters in start/stop equipped vehicles will probably outlast ones without it.
Start/stop feature only works in the right conditions. So if the engine isn't to operating temp, or the climate control is in a high demand state it won't turn off etc.
Start/stop is here to stay, might as well learn to like it. I have no real complaints, and if I don't want it to shut off I simply press the button right on the console. My Jeep Grand Cherokee also had it, worked exactly the same.
 
#9 ·
I have had some loaner cars with it and I liked it at a stop light but not so mush at stop signs. But all I had to do was blip the throttle and it would stay running. I did not have it during summer at 115 degrees in the shade so I do not know how that A/C will work. It uses capacitors to power the starter not the battery.
 
#13 ·
I got my 2016 ATS in December, so I'm still in the "relatively new" category, but it's more exposure than a rental or something, and I have to agree that I think it's one of those things you just get used to. It's definitely nice to have the override button, but as someone else said, it's actually nice sitting a light in silence with the car shut off.

I disable it during the slow creep of rush hour traffic - that just becomes a huge nuisance - but for the average drive in normal traffic, where you're sitting at most lights for 30 seconds or more, I don't even bother disabling it.
 
#14 ·
I don't have a problem with it in general but certain things it does really irritate me. I wish the amount of time it had to sit stationary before stopping was a setting. Loaner I had, if you came to a stop sign and a complete stop for even a second it would turn off the car.

I also didn't like that whenever the car was in "Park" the car was running. Seems like this could be the time when it would have the biggest gain. There is a school near me and virtually everyone sits for long periods of time with the car running, it in Park and regardless of the weather. If the car is in Park, Stop/Start should turn the engine off when it isn't needed.

Then with the XT5 loaner I came to a stop to get out of the car, when I stopped the car the engine would turn off, then when I put it in Park the car would turn on, just so I could turn it off. So every time I was going to get out of the car there was an unnecessary start. I don't want the engine to start just because I put it in Park and can't think of a time this would be useful. If they are worried about the person that forgets to turn off the car and leaves to go inside, make it a setting or sound an alarm whenever you get open the door but haven't turned the car off.

Also, switch on the dash or console needs to stay. If I am in a line, like paying to get out of a parking lot where the line is moving pretty quick I don't want the car to turn on and off every 10 seconds, 30 times.
 
#15 · (Edited)
This is the first car I've had with it, but I've experienced it before as a passenger in a BMW 320i and a Benz GLA. Both of those were VERY noticeable when it starts back up...the car shudders. Plus the GLA turns into an oven at stop lights in the summer! In comparison, the ATS 3.6 is very smooth...sometimes unnoticeable. Still, although it's rather seamless, it can be uncomfortably odd during stop-and-go traffic, which is when I usually disable it. But I don't mind it so much during stop lights. What bugs me though is that it always defaults to on when you start up. If I choose to shut it off, it should stay off until/if I turn it back on.
 
#16 ·
I got a '17 XT5 loaner today while my ATS non-cue infotainment system and entire center console was getting a reprogram after completely loosing power (2 months out of warranty only 41k miles).

The XT5 was pretty smooth but, as with all start/stop vehicles I've driven, I just don't like that it is very hard to not notice.

On top of that the XT5 also toggles between V4 and V6 mode. I must say I couldn't tell if it was running on 4 or 6 cylinders or when it transitioned, well done.
 
#17 ·
Thanks for the report Ron and hopefully your dealership looked into a goodwill adjustment for your reprogram.

I hope that this V4/V6 mode change works better with the transmissions used in the newer Cadillac models compared to the problems experienced with the V8 engines and automatic transmissions used in some other GM products. GM has gone through at least 3 torque converter revisions for the 8L90 since its model year 2015 release and now are trying a filter change and triple fluid flush with a different fluid to address an issue with transmission shudder and RPM fluctuation when V8 engines are in V4 mode. My Z06 has this AFM (active fuel management formerly called DOD or displacement on demand) but I leave the transmission in manual mode which is the only way to keep it from activating. In order to reduce vibration from the engine operating in V4 mode the mechanical clutch in the torque converter is rapidly modulated to absorb the vibration and it apparently doesn't stand up well to this type of service. Maybe the 3.6L and associated transmission will fare better.
 
#18 ·
For the most part the only way I know my ATS is in 4 cyl or 6 cyl mode is the indicator on the dash that tells me. Its a pretty seamless system. If you have the radio down low enough with the windows up you can hear the exhaust note change, but that was only more obvious since I installed the GM accessory performance exhaust system. Even though I dont mind the start/stop system, it would be nice if it was a little less noticeable. Sometimes it works very smoothly and its hard to detect, other times you might get a little jolt or shake. Overall not bad, and it works literally identically to start/stop systems I have experienced in other brands as well.
 
#19 ·
I had concerns about it but i have grown to like it. I disable it for stop signs, in traffic, or other quick stops, but i put it on at long lights. I love not burning gas while sitting for a light. I accepted it because in the future all cars are going to have it, so you need to embrace it. It is easily disabled with the press of a button behind the stick, so it's really not an issue. I am not worried about the starter either, get back to me in about 10 years and i'll let you know if there were any problems, because i bought this car to keep it for 10 years.
 
#20 ·
Not sure why all the hate? Having driven 2 Priuses over 7 years & logging over 150K between the 2 - I have to say that Start/Stop seems like a no brainer. Sitting still while the engine is idling seems so wasteful and down right "old fashioned." With the Prius I never had an issue with the engine not starting up soon enough from a full stop. Integration was very seamless and I loved how quite it was while waiting at an intersection - very serene. I wish my ATS really had this feature.
 
#26 ·
Or worse than that someone stalls in an intersection and gets killed because they couldn't get out of the way fast enough. Acceleration is just has important as brakes as far as safety features go. I found this out in my '99 BMW. It was early drive by wire and they tried to do this fancy thing were the software would "learn" your driving style and automatically adjust the accelerator. It kept trying to "learn" for the life of the car and there was no way to turn it off. So every time you pressed the gas you had no idea how it would respond. In some cases it would just not respond for up to 5 seconds leaving you stranded in the street. Almost got me killed several times. Finally had to trade in the car at two years, it was just to dangerous to drive and there was no way to turn the "feature" off.
 
#27 ·
Stop start in the future likely will not be easily defeated and it will depend upon future EPA regulations and interpretations for CAFE and "sticker" MPG which are calculated differently. In general, to be acceptable for these calculations the setup must be the usual or normal operating condition(s) for the vehicle. This is the primary reason you see manufacturers moving towards 0W20 as the required oil weight because whatever is called for in the manual is what is used for the EPA drive cycle testing and the very thin oil provides a mileage advantage, particularly since cold/warm-up operation is part of the prescribed drive cycle. For mileage increasers like stop/start if they are too easily defeated/avoided then it is likely they will not be acceptable for use in these calculations. The Chevrolet I rented in Florida last year had no shut off for start stop and could only be defeated by leaving the automatic transmission set to manual mode and shifting manually. For the same reason I operate my 2016 Z06 in the manual shift mode when I don't have a Range module plugged in because this is the only way to defeat the AFM system which switches from V8 to V4 mode under light load conditions but this results in very little mileage gain and some potentially bad side effects.
 
#30 ·
Another concern with stop/start technology is you are greatly increasing the number of engine starts over the life of the engine and it does take a finite time to build normal oil pressure at each start. The main bearings are the most subject to additional wear however this hopefully won't be an issue as long as the newer bearing materials designed for this service are used; they are designed to better withstand that short period of time when there is not a pressurized oil film and actual crank to bearing surface contact is taking place. It doesn't really matter for those of us who tend to trade a car at lower mileage but for those planning on running up to high mileage or buying used needs to consider this potential wear issue. A complicating factor is to make the stop/start as transparent as possible the engine cannot have a delay period for pressure to build between starting and having full load applied.