kurtatx

There's a really good discussion of Engine Auto Start/Stop in the 5G TLX board, but I want to hear impressions from other people with various models as well as from people who will have the feature on their future cars.

I'll start
2017 Audi A4
While Auto Start/Stop is generally panned by car people, the A4 does a fine job of it. I don't mind the thing starting and stopping when I'm on my 5 mile commute to the office. That being said

• It's not particularly subtle. The VW turbo 4 is a bit of a jolt
• In traffic, the car stops the feature after a while, but the time prior is very odd (It's almost randomly shutting off and starting again in heavy traffic)
• When the engine starts up, the window briefly pauses

The good news for detractors, particularly in the American south, is the warm weather makes the car less and less likely to stop.

Sarlacc

Our x3 has it. I'm indifferent. But I really hate when it shuts off when are in the middle of an intersection waiting to make a left. That's unsafe to me so I either disable it then or make the engine turn back on.

I also dont like it in hot weather because the AC stops cranking when it's off.

kurtatx

Interesting. Mine like never stops in the heat. It will just crank the AC and keep running.

The Dougler

iTrader: (1)

I have it in my A4, in general I'm fine with the feature but to your point it should never turn off when a turn signal is on for safety reasons. With the A4 you can control it with pressure on the brake pedal, not sure if your X3 is similar.

kurtatx

I forgot that part. Yeah, it's pressure sensitive so you can stop the car without the engine stopping.

Sarlacc

The AC keeps running but you can tell the cooling unit is off, and its just venting air.

Same

imj0257

iTrader: (1)

Mine is subtle, no jolt or anything when it turns off/on and it does it pretty quick, so really not an issue if I'm at a light waiting to make a turn. That being said, I'm not really a fan of the feature in the first place.

I don't know if it is the heat down here like someone mentioned, but sometimes it works and sometimes it doesn't when it is turned on. If I remember, I always try to disable it when I start it up. But I like to drive in Sport+ mode a lot and it is automatically disabled in that mode anyways.

wackjum

I don't own any cars with auto start/stop, but I have some experience with them.

My first experience was in a ~2011 BMW 640 and it was pretty terrible. You definitely felt the car starting and stopping. I don't know if it was because the engine is larger or because the technology was still immature. It also took a long time (relatively) to startup and to me it was completely unpredictable when it would start or stop.

My second experience was in a 2017 Chevrolet Cruze rental that had start/stop. The implementation was a lot better. I quickly learned how much brake pressure you need to apply in order to trigger or not trigger the stop functioning and the starting process was a lot smoother.

With the Cruze experience, it was so predictable and seamless I would not have a problem with that technology. The BMW experience was terrible. I don't have enough experience to tell if the technology has just matured or it is better implemented in smaller engines. If this is the case, it is ironic since the larger engines would benefit the most from it.

One thing that happened in both instances was that the A/C compressor shuts off and only the fan is running. In Texas, the coils will start to warm up almost immediately, so this can be a problem in a lot of stop and go traffic. The real problem with the coils warming up is that moisture starts to evaporate off the coils and humidify the air, which is a serious comfort problem in the confines of a car.

But the Cruze would fire up the engine if the coils got too warm. I don't remember the BMW making this distinction.

te3point5

I had a 5 series rental a couple of years ago with it. Had the car for a month, after the first week, I hardly noticed it stopping and starting. Agree with Sarlacc though, the AC getting hot is a major draw back on a super hot day.

thoiboi

Hate it. Hate it. Hate it.

RDX10

I have some questions, comments, and concerns about this topic.

Questions: Does this cause issues for the starter and other associated parts? Like will it cause premature failure on those parts? If so, does the cost of replacement overtake the savings?

Comments: I had a 2015 (iirc) ILX hybrid loaner (the biggest POS car I have EVER driven in my entire life) with stop-start technology. Let me just tell you guys the first time I approached a turn at an intersection and the car turned off I nearly shit myself. I had zero idea what was going on. Till I seen "stop-start" flash on the dash screen.

Concerns: As Sarlaac pointed out, this technology is scary on intersections and it really does seem like a lawsuit waiting to happen. I realize that most systems start fast these days, but I still want my car on at all times unless I turn it off.

So that leaves me with a good middle ground. The 2010+ Mitsubishi outlander (off the top of my head) goes into neutral at stops and automatically engages drive the second you take your foot off the brakes. This seems like a better solution that fully turning the engine off. I test drove a 2011 outlander XLS before buying my (POS) MDX and I did not feel the car going into and out of neutral at all. I liked that. But I mean I can easily throw my car into neutral during long lights (except I sometimes forget to throw it back to drive lol).

Costco

I immediately turn it off in every vehicle I drive that has it.

No doubt an annoying feature to improve city MPG ratings and appease EPA regulations or whatever. Reminds me of skip shift... as long as it's easily disabled, I guess it's better to have it than not, for those that don't mind it.

Costco

As far as wear and tear goes, I have to say I am not too familiar with the non-hybrid Germans with their stop start. There is obviously going to be much more wear on the starter if it has to crank the engine over many more times.

But on Toyota and Honda hybrids, they eliminate the starter (and alternator) with a motor-generator. At least in my experience, I have never seen one of those units need replacing. It occasionally needed replacement on the first gen Prius, but 2004-up have been solid.

KaMLuNg

iTrader: (5)

last month when the V was in for a S/C service, they gave me a brandy dandy new XT5 that had it... i hated it... and i couldn't figure out how to turn it off...

it would jolt when it would kick on and exactly what Sarlacc said, waiting at a stop sign for an opening and trying to go was such a huge delay... i also found that in stop and go traffic it was annoying... i thought to myself the wear and tear on the starter and engine can't offset the fuel savings long term...

justnspace

iTrader: (1)

I occasionally stall in traffic with 6MT, does that count?

SamDoe1

My Jeep has it, I don't mind it at all. It's pretty seamless and doesn't bring a lot of attention to itself. After a while, I start thinking about all the gas I'm wasting sitting still at a traffic light. Left turn thing isn't really an issue for me, the engine starts up in the time it takes me to move from brake to gas every time. It'll also restart itself if it needs AC and also will disable start/stop in 4WD Low and certain drive modes. I wish it knew when I had a trailer hooked up to also disable it too but I guess we're not there yet.

DIY start/stop feature

juniorbean

iTrader: (5)

The E63 has it. Honestly, it works pretty well and is that not that intrusive. Pretty seamless actually. It does not shut off the other servies, so HVAC runs, radio/electronics stay on... etc. We don't have the issue Sarlacc mentioned with it shutting off when trying to turn. Maybe it's smart enough not to do that when the turn signal is on?

neuronbob

What prompted kurtatx's starting this thread was our discussion in the TLX forum about this awful trend.

In the TLX, the steering wheel locks when the engine shuts down. If the wheels are turned in this situation, I can't turn the car for a few microseconds. As soon as I start to turn the steering wheel, the engine turns on (which, by the way, I can feel unlike in my RLX SH, when I felt nothing when the engine turned on/off), then the steering wheel unlocks.

I hadn't even considered what happened to the AC, I'm sure it's the same in the TLX as you guys describe above.

I hate it. Thankfully, Acura gives you an easily accessible button so you can turn it off. Even better would be a setting in the user menu allowing you to keep it off. I'm willing to suffer a miniscule worsening in fuel economy to make this go away.

Speaking of fuel economy, I'm doing a test. This tank of fuel, I'm using auto-stop. Next one, I won't. We'll see what the difference in FE is.

1killercls

My understanding is you can disable it with a VAG.com

00TL-P3.2

My F150 has it, only the 2016 & 2017 2.7 had it, all F150s 2018+ will have it.

I don't mind it, now that I'm used to it. I've learned how to work the system to keep it form shutting off when I don't want it to.
It also has conditions that will automatically disable it: max a/c, steering turned more than 90*, trailer connected, tow/haul mode engaged, and a few others.
2017+ F150s, Sport mode disables it as well.
Light brake pressure is usually how I keep it from engaging.

With it, I've gotten near 20 mpg commuting.

As mentioned above, it does 'lock' the steering, I haven't tried to force the wheel to see if it'll turn.

juniorbean

iTrader: (5)

Wow, that's insane. The Mercedes is NOTHING like that. It's very unintrusive. What you described would drive me nuts and I would likely disable it all of the time...

SamDoe1

Mine doesn't lock the steering, it'll turn the wheels if it has the juice to do so (EPS) and if not, it'll turn the motor back on.

Sarlacc

bmw locks the steering, no good

RDX10

That's exactly what comes to mind with these systems. I can't be saving more than a few cents with this gimmick, I'm certain the cost of starter motor replacement would outweigh the savings.

I didn't even think about that, or I mean I didn't even think they would be STUPID enough to lock the steering column too. So your telling me that the engine turns off and the steering wheel locks at intersections in some cases? What a load of bull.

SamDoe1

A few cents here and there definitely adds up over the course of ownership. Also, it really doesn't hurt things to shut the motor off and then automatically start it up again.

Also, the starter motor and flywheel are heavily upsized and designed for cars that have this feature.

00TL-P3.2

I don't know that mine 'locks' the steering column, like it does with the truck off, but it is significantly heavier, to the point I haven't attempted to turn it while the engine is off.

SamDoe1

Electric power steering right? Shouldn't matter then. If the system needs power, it'll kick the engine on.

kurtatx

Ditto. It's technically a safety feature so you don't go careening into cross traffic if you get hit from behind.

The A4 will not turn off the engine if the wheel is rotated in either direction

Sarlacc

Interesting I haven't tested that, or researched bmw's system much. When I pull into intersections I always keep my wheels straight for safety, I don't turn until I'm clear.

I do know the system is brake pressure sensitive like many of the others.

JT4

We have it in the Q7 and I have tried to get used to it but don't like it. So I am very happy that Audi put a simple button right on the dash, so no menus to go through just a simple push of the button turns it on/off. I am also pretty sure that it will not activate if I have the Drive Select in Dynamic mode.

kurtatx

Correct. In Dynamic mode, Engine Start/Stop is disabled. I just can't bring myself to drive in dynamic all the time.

RDX10

No you're right, it does add up. But I'm thinking it might not add up if it causes premature wear. Now on the other hand if like you say (and I do agree) they most likely do beef it up, then it's probably a moot point. I haven't owned a car with this "feature" yet. But I do know it won't be a selling point for me whatsoever.

RDX10

X2 on this. I had sport mode on my RDX as well as Touaregs and X5's and it really is a very unpleasant driving experience. I mean I liked being able to throw it into sport mode for some spirited driving here and there. But no way in hell could I drive in sport mode all the time. Way too aggressive for me.

fsttyms1

The single hardest moments for an engine/bearings are the shock at startup

RDX10

This was my impression as well.

kurtatx

I honest to god have no idea how it works, but haven't hybrids like the Prius been starting and stopping their engines constantly already anyway? I mean a Prius restarts the engine every time the car hits 17 mph anyway. I'm not personally too worried about it.

RDX10

I drove a camry hybrid a couple months ago and I noticed the enginge would not start when the car started, like it was running on pure EV mode until I went faster/prodded harder. That was a WEIRD feeling.

Costco

I mentioned above that the Prius and other hybrids do not have a starter. They (Atkinson cycle) also operate different than most automotive combustion engines (Otto cycle). I don't know what the difference is in regards to wear and tear, but without a doubt it is higher than otherwise. Whether it is an issue or not, I don't know either.

It could be one of those things that is a new issue entirely, or maybe not at all. I am sure the manufacturers designed things with the start stop in mind, but...

kurtatx

I bought a German car. I know the damn thing is going to break, lol.

fsttyms1

Hybrids dont use the starter to get the motor spinning, They use the electric motor attached between the trans and engine to get the motor spinning before there is any combustion detonation like during a start up, which also gets the oil pump spinning and lubricating.