Auto Start Stop on ICE cars

[GoTslaGo]

Just a personal commentary.

All my recent loaners from BMW have had auto-start stop features. Basically if you're in drive and come to a complete stop the engine shuts off. Before the Tesla I found this tremendously annoying and had to switch their drive mode to "sport" or disable to feature manually.

My latest loaner however, I couldn't help but to notice how annoying the idling engine felt and sounded. It was a newer 4 cylinder engine and it was much rougher than the 6 cylinders I'm used to. Once I activated the start-stop feature, it felt great. Made me feel like I was temporarily sitting in my (wife's) Model S at the longer red lights.

But a disconcerting feature I discovered this time is that it really Shuts Down the car (in the past I usually just disabled this feature). I almost always come to a complete stop at a stop sign, and with an idling car you can still turn your steering wheel to prep for a turn. Well with the start-stop feature I had no steering! Pretty disconcerting as I needed to jump into a busy street and basically had to "run" the stop sign. As the car shut off I could feel my steering tighten up, so I let up the brake and the car started up again.

It seems all these fuel efficiency strategies BMW has pursued is really killing the driving experience compared to the older ones. Especially if you want to decrease your own negative impact on the environment and use their Comfort/Eco modes. Otherwise you'll always have to drive in Sports mode (more wasteful). I am glad that BMW is really looking hard at electrifying their fleet, or so I have read. Until then....

I am really glad that I convinced my wife that we should own and drive Teslas. Once we've sold our old house, it'll be time for a new Model X...

 

[deonb]

I also had one of those as a rental a couple of weeks ago. A Volvo.

Wow, what a horrible experience. Every time I come to a stop the AC would shut off. I also had to switch it to sport mode to work around that.

 

[GoTslaGo]

Yes, the first one we ever tried (years ago) worked once. Then never stopped again as the AC needed to keep running. After that we ran all our loaners in Sports mode or manually disabled it. Only reason why I didn't run it in sports mode this time was how rough the 4 cylinder was and uncomfortable idling was. Pretty much defeats the purpose IMHO.

Service guys also just shrugged their shoulders when we brought up burning out the starter motor with repeat start-stop.

Time to go electric...

 

[bikeandsail]

My current car a Lexus RX 400h hybrid normally stops the engine at a stop, of course it is made for that duty.

It still runs great but since the wait for the X has been longer than planned it has 219,500 miles on it!

 

[JPP]

See this:

http://www.nytimes.com/2016/04/08/a...on&region=bottom-well&WT.nav=bottom-well&_r=1

 

[djplong]

I had that feature on a rental we had in Germany. I'd reserved a diesel Passat wagon. When we got to the agency, they asked if it was ok to substitute a different car for the same price - in this case a black Mercedes E-Class turbo diesel wagon! Um - SURE!

They set the car's Nav system to English (how nice of them!) and off we go. I'm 6000 miles from home in Nuremburg. Pull up to a red light, stop and the car DIES! I'm worried and trying to figure a way back to the rental agency while I figure out how to get the car to turn back on. As soon as I pick my foot up off the brake pedal, the engine starts right back up..

Ohhhhhhhhh.... It has THAT feature....

It took some getting used to.

 

[kort677]

I believe that stop start is required in some countries and isn't uncommon here in the US. my wife's MB has it

 

[1208]

Its a pathetic joke.

Hopefully it will have the adverse effect of people wanting to buy EV's more than they otherwise would have.

 

[Skotty]

In order for stop/start to not compromise the capabilities of the vehicle, all accessories would need to be powered by the battery (including power steering, a/c compressor, smog controls, possibly supplemental vacuum pumps, etc). Is that how most are doing it? Seems you might would need a bigger battery for that, at which point you are one regenerative braking system away from just being a hybrid.

 

[spottyq]

In order for stop/start to not compromise the capabilities of the vehicle, all accessories would need to be powered by the battery (including power steering, a/c compressor, smog controls, possibly supplemental vacuum pumps, etc). Is that how most are doing it? Seems you might would need a bigger battery for that, at which point you are one regenerative braking system away from just being a hybrid.

Why bother ? Start/stop is rarely stops the engine for more than 30s. For such a small duration, all belt-driven systems can be stopped and you'll even still have cold air because the a/c chiller won't have time to warm up and the fans are 12V; all vacuum systems have a small reservoir etc.
Why would you need smog control if the engine is running ? (serious question, I wasn't even aware these would require something else than 12V power.)

I regularly drive two recent (< 5 years) cars from different brands with start/stop and I haven't been annoyed by the lack of power steering. I can't say if it is because I don't turn the wheel when the engine is stopped or the power assist is actually working.

Obviously, that requires the car to check if these systems do not need to be recharged before stopping the engine (ie. check 12V battery SOC, vacuum status, etc. and eventually temporarily disable start/stop.)

 

[kort677]

for those of you who abhor the stop/start feature becoming mainstream you can thank your local tree huggers for getting regulators to implement the feature.

 

[Skotty]

Why bother ? Start/stop is rarely stops the engine for more than 30s. For such a small duration, all belt-driven systems can be stopped and you'll even still have cold air because the a/c chiller won't have time to warm up and the fans are 12V; all vacuum systems have a small reservoir etc.
Why would you need smog control if the engine is running ? (serious question, I wasn't even aware these would require something else than 12V power.)

I regularly drive two recent (< 5 years) cars from different brands with start/stop and I haven't been annoyed by the lack of power steering. I can't say if it is because I don't turn the wheel when the engine is stopped or the power assist is actually working.

Obviously, that requires the car to check if these systems do not need to be recharged before stopping the engine (ie. check 12V battery SOC, vacuum status, etc. and eventually temporarily disable start/stop.)

Stop/start sounds like an exercise in maximizing the cons and minimizing the pros.

 

[Az_Rael]

I rented a Volvo once that had it. Thought it was going to kill me several times when it would shut down just as I was about to goose it to get into a busy traffic lane. The problem with it, is there is a hesitation when the car starts back up before you can get full power. I have also read accounts, that when they do fail, the car won't start potentially leaving you stranded in a busy intersection.

My Volt does the same thing when I am on ICE mode with one key difference. The giant battery. So even if I hear the gas engine turn off at a light that has zero effect on my ability to punch it and go since the battery pack is what is actually moving me. Same for any hybrid.

This regular battery non-hybrid ICE car start/stop thing will probably only last as long as those seatbelt auto tracks they used to have on cars. Besides, I have read the gas savings estimates are dubious at best.