Engine Stop/Start Seems a Ludicrous Concept to Me Now that I've Driven It

[CR94]

Originally Posted by nicholas
... It is easy math - - - - Places with high population densities have the most to benefit from it, ...
Yes. Contrary to some thoughtless posts (not yours), the savings from start-stop for owners who live in areas with congested traffic and a lot of red lights is greater than will show up in EPA tests. That's because their tests, even the "City" one, do not include a realistic percentage of stopped time.

Ludicrous or annoying programming details of start-stop of some brands and models does not make it a "ludicrous concept" in general.

 

[P10crew]

I've never been around a vehicle with this stop start. What is restarting the motor? The normal gear reduction starter?

 

[weasley]

Usually, yes. I remember reading years ago about one OEM who was using the crank angle sensors to know which piston was under compression when it stopped, then squirting (through DI) and igniting that cylinder to get started again - not sure if it lasted as an idea.

 

[Benzadmiral]

Originally Posted by jeepman3071
Originally Posted by MCompact
Not being able to disable the feature would be a deal breaker.


This.

I'm not totally opposed to start/stop, but the way it is implemented makes the difference. BMW allows you to turn it off, and the F30s I've driven were pretty smooth. The GMC mentioned above that doesn't allow you to shut it off, and re-starts the engine when it is put into park would be a 100% deal breaker for me.

True enough. My 328i has it, and I usually leave it disabled, but the few times I have tried it, it was pretty seamless. At present I'm not in long-stop traffic enough to make it worth while using . . . though if premium fuel soars this summer,I may try it a bit more!

 

[MCompact]

With the B48 in my X3 loaner you have to concentrate or watch the tach to tell when it cycles on and off.

 

[ddrumman2004]

I defeated the start/stop feature on my 2018 F150 by jumping out the switch on the dash. What I can't figure out is how it worked so smoothly.
By that I mean you could hear the starter when cranking engine the first time after manually killing the engine with the key switch. But when the stop/start was engaged, the engine stopped and started back up without hearing the starter engage. At least they sure made it appear that way.

 

[PimTac]

Originally Posted by ddrumman2004
I defeated the start/stop feature on my 2018 F150 by jumping out the switch on the dash. What I can't figure out is how it worked so smoothly.
By that I mean you could hear the starter when cranking engine the first time after manually killing the engine with the key switch. But when the stop/start was engaged, the engine stopped and started back up without hearing the starter engage. At least they sure made it appear that way.




Some manufacturers use a system of firing the plugs with fuel injected to restart.

 

[atikovi]

Originally Posted by PimTac
Originally Posted by ddrumman2004
I defeated the start/stop feature on my 2018 F150 by jumping out the switch on the dash. What I can't figure out is how it worked so smoothly.
By that I mean you could hear the starter when cranking engine the first time after manually killing the engine with the key switch. But when the stop/start was engaged, the engine stopped and started back up without hearing the starter engage. At least they sure made it appear that way.




Some manufacturers use a system of firing the plugs with fuel injected to restart.


Which ones? That's cleaver if it works reliably. I assume a piston has to be very close to TDC for that to work.

 

[PimTac]

Thirty seconds on DDG is all it took. I'll leave it up to you to find more.

https://www.mazda.com/en/innovation/technology/env/i-stop/

 

[Rumble]

Maybe this explains why so many people are rolling thru stop signs & running red-lights these days. "But officer, if I stopped, my engine would cut-off!"

 

[Andrew1972]

Been renting a Chevy Malibu with the feature. Since I already own it and used to it I can give feedback. It works very smoothly and flawlessly. Great job GM!

 

[4WD]

IIRC … with the last Malibu (liked it fine) that I rented … I was bumping it into N at red lights and it would stay running

 

[Cujet]

Originally Posted by rooflessVW
I like it. I see no reason for idling at a long light or the drive through.


Here in South Florida, a functional AC is rather important in summer.

My 2018 F150 shuts off and the AC blower goes to "low". At which point the cabin starts heating up, sometimes uncomfortably. At which point the engine starts again. I'd rather have the AC on full blast.

Also of note, as the truck is getting a few miles on it, it's taking longer to start.

 

[racerviii]

I can see it now. As these stop/ start equipped cars get older, engines will fail to restart sometimes and then accidents will happen where it wouldn't have if the driver was able to make a quick getaway.

 

[gonefishing]

My work car (18 Equinox 1.5) has start/stop with no disable button. I have found that if the gear selector is in manual it disables the start stop. Not the most convenient method (shift into manual then used the plus/minus button to get it up to 5th or 6th gear).

 

[AC1DD]

It would be interesting to hear from professional techs on how this feature can be disabled via the manufacturer's scan tools permanently.

I'm sure it can be done.