# Automotive “Start/Stop” Systems -? **URL:** \ **Category:** Factual Questions\ **Created:** [June 18, 2025, 10:33pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820 "2025-06-18T22:33:48Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [June 19, 2025, 10:27pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/41 "2025-06-19T22:27:02Z")
> [@LSLGuy](#): > > I suppose having flown airplanes for a long time where paying continuous subconscious attention to the sounds and vibrations is a big part of the game has something to do with it. Any unexpected change in vibration is bad news, and perhaps catastrophic news. Same with tractors and plow trucks. Sound and vibration are key inputs for the operator. Because of that, I don’t listen to music when on/in them. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [June 19, 2025, 11:50pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/42 "2025-06-19T23:50:10Z")
The first time I noticed this was on the Montreal city buses. Of course they spend a lot of time stopped so the savings are probably major. I assume that if there real maintenance issues, they wouldn’t do it. The engine simply restarts without any cranking, which is why it surprised me. I’ve never driven such a car, but I see no reason it would bother me. (My car is vintage 2007.) ---
**Author:** ![Railer13](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/railer13/32/9742_2.png) [@Railer13](https://boards.straightdope.com/u/Railer13)\ **Post date:** [June 20, 2025, 12:24am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/43 "2025-06-20T00:24:21Z")
> [@enipla](#): > > Same with tractors and plow trucks. Sound and vibration are key inputs for the operator. And combines. I operated a combine for three summers on a harvest crew. Not noticing a strange sound and shutting down immediately could cause great harm to an extremely expensive machine. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [June 20, 2025, 12:32am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/44 "2025-06-20T00:32:59Z")
> [@Hari\_Seldon](#): > > The first time I noticed this was on the Montreal city buses. Of course they spend a lot of time stopped so the savings are probably major. I assume that if there real maintenance issues, they wouldn’t do it. The engine simply restarts without any cranking Interesting. I’ve never heard of that system being used on buses. Here you’re dealing with a diesel engine so auto-start without cranking would seem to be an even greater challenge. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 20, 2025, 12:37am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/45 "2025-06-20T00:37:44Z")
I don’t see how you could start a diesel w/o a cranking motor. But again, electric starter motors for ICE or diesel engines is now 100 year old tech. Not hard to make predictably reliable; at least assuming the bean counters don’t insist on it being under-engineered for purpose. The big difference between lighting off a 1960s ICE or diesel and one today is that the fuel injection and ignition is perfect. And the engine is nice and warm. The first cylinder to complete an intake and compression stroke will fire with 100% reliability. So assuming an 8 cylinder engine, 1/2 of a crank rotation will fire some cylinder. Which will get the engine running. That doesn’t take long in time, nor much electric power from the battery, nor much wear on the starter. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [June 20, 2025, 3:47am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/46 "2025-06-20T03:47:36Z")
> [@Bullitt](#): > > It cannot be configured to Off, so I disable it every time I start my car. It is a simple button push from the Home Screen. It can be disabled by installing a module in the wiring harness. I did so on my '19 Forester and my '24 Outback. Once I turn it off, it stays off unless I re enable it. Used software to disable on Ford products. ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [June 20, 2025, 7:57am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/47 "2025-06-20T07:57:48Z")
Good to know. I’ll have to look into that. Thanks. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [June 20, 2025, 8:14am UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/48 "2025-06-20T08:14:50Z")
> [@LSLGuy](#): > > I don’t see how you could start a diesel w/o a cranking motor. But again, electric starter motors for ICE or diesel engines is now 100 year old tech. Not hard to make predictably reliable; at least assuming the bean counters don’t insist on it being under-engineered for purpose. My Nissan Qashqai, which I mentioned above, is a diesel and has start/stop as described. Model year is 2016. Here in Europe, diesel-engine vehicles are more common in the passenger-car market than in the US. Also, as noted, it’s a stick shift, which is definitely the norm here. I listened to the automatic start on the drive into work this morning. There is a small but perceptible crank, compared to my wife’s Yaris hybrid where the restart is smooth and essentially invisible (per discussion above). However, the crank action is quick, gentle, and quiet. The engine starts right up. I regard this as a solved problem. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 20, 2025, 3:16pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/49 "2025-06-20T15:16:24Z")
> [@Cervaise](#): > > I regard this as a solved problem. As do I. All the complaining about the mechanical side of it is just curmudgeonly backwardness. I’ve fussed upthread about the psychological side of it, but based on all the yakyak here I think I’ll reconsider leaving it enabled and see what it takes to get used to the idea. Not that I care about the fuel savings given my driving habits, but I don’t like siding with the aging curmudgeons. Next thing you know I’ll be wearing onions & shouting at clouds. Don’t go there. Seriously. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [June 20, 2025, 3:20pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/50 "2025-06-20T15:20:45Z")
> [@LSLGuy](#): > > I don’t like siding with the aging curmudgeons. 👍 This motivates a remarkable fraction of my own choices and behavior as well. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 20, 2025, 3:29pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/51 "2025-06-20T15:29:25Z")
One of my mottos: > You’re only as old as you behave. Which is an important distinction to me. It’s one thing to claim you’ve got a youthful attitude or whatever. But until you demonstrate it with outward behavior, it’s not obvious that you’re not fooling yourself. ---
**Author:** ![Railer13](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/railer13/32/9742_2.png) [@Railer13](https://boards.straightdope.com/u/Railer13)\ **Post date:** [June 20, 2025, 3:42pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/52 "2025-06-20T15:42:43Z")
My wife’s car (2019 Toyota Highlander) has this feature. It can be manually turned off each time via a switch that’s located left of the steering wheel, down by the fuel filler door release. When we first got the car, she would turn it off each time she started the car. But she never does anymore, because she’s gotten used to it, and it’s not a big deal when waiting at a red light or stop sign. And if saves a few pennies on fuel costs, why not leave it enabled? ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 20, 2025, 3:45pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/53 "2025-06-20T15:45:20Z")
Let’s say you have the air conditioning on, and you’re stopped for a while. Will it automatically restart the engine if it senses the cabin temperature increasing? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 20, 2025, 5:54pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/54 "2025-06-20T17:54:22Z")
Yes it will. Need for heat, or AC, or need to move the car. Any of the three will restart the engine. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [June 20, 2025, 6:09pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/55 "2025-06-20T18:09:08Z")
> [@LSLGuy](#): > > > You’re only as old as you behave. It’s never too late to have a happy childhood. ---
**Author:** ![Pork\_Rind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pork_rind/32/111_2.png) [@Pork\_Rind](https://boards.straightdope.com/u/Pork_Rind)\ **Post date:** [June 20, 2025, 6:14pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/56 "2025-06-20T18:14:43Z")
The only car I’ve driven where I genuinely thought the automatic start stop was a detriment was my wife’s RDX. As it was configured in that car, I felt like it was just a hair too aggressive. Couple that aggressiveness with a power steering system that was fractionally slow to build pressure on restart, I get into situations maneuvering in parking lots where it would turn off and then come right back on, but I’d have to fight the steering wheel for like an eighth of a turn. Both our current cars are calibrated a little more generously in that they will not turn off if they feel like you’re in a situation creeping and maneuvering. And they both have electric power steering, which means that the steering field is the same, even if you start to crank the wheel before the car starts up. ---
**Author:** ![hogarth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hogarth/32/1773_2.png) [@hogarth](https://boards.straightdope.com/u/hogarth)\ **Post date:** [June 20, 2025, 8:09pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/57 "2025-06-20T20:09:22Z")
> [@wolfpup](#): > > Interesting. I’ve never heard of that system being used on buses. Here you’re dealing with a diesel engine so auto-start without cranking would seem to be an even greater challenge. Hybrid diesel-electric buses are relatively common in Toronto (but there are still lots of pure diesel buses in service). ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [June 20, 2025, 9:10pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/58 "2025-06-20T21:10:55Z")
Wow. Really wrong reply! Please ignore. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [June 20, 2025, 9:14pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/59 "2025-06-20T21:14:53Z")
Unlike many of my compatriots, I drive a car with an automatic gearbox. When I am stopped in traffic and the engine stops, I am happy that it is not only saving petrol, but reducing wear on the gearbox. It does use the starter to re-start, and I am aware that the starter motor is designed to do this. Also, the battery is a heavy duty version. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 20, 2025, 9:49pm UTC](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820/60 "2025-06-20T21:49:37Z")
[aside] That is _exactly_ what I’m trying to do. In my case childhood was pretty darn good. But it fell apart at “young teen” and didn’t really recover until “30-something”. There’s a couple of ~15-year long holes in my 60+ years that _really_ need do-overs or compensatory refilling while there’s still time. [Previous page](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820.md?page=2) [Next page](https://boards.straightdope.com/t/automotive-start-stop-systems/1019820.md?page=4)