Stop-Start Technology

It looks like Mercedes has figured out how to make it work properly.

I remember we first encountered it about seven years ago while shopping for VWs (we ended up getting a Toyota instead). I’ve been getting it in rental cars a lot lately, and I don’t like it. It seems like its likely to make a starter fail a lot sooner, unless they make it a lot more rugged. If I owned a car with it (that wasn’t like the Mercedes set up) I’d probably disable it.

16 thoughts on “Stop-Start Technology”

  1. Sounds like a better idea for … hybrids than ICE vehicles. Only run the ICE when you need it.

  2. Stop-start is a disaster in places where you need AC and you’re in the city, or at least it was just a couple of years ago, because it’ll stay off at a red light long enough for the AC to stop cooling. You wouldn’t think a minute and a half would be long enough for it to get hot, but it sure feels like it. (Actually, before the temp starts going up, you get that nasty phase where it stops dehumidifying the air.) I had some issues with my car around 2018, and I had several loaners from the dealer, so they gave me stuff like the Trax and Cruze. So it could’ve been a Chevy or lower-end car issue, but it doesn’t endear you.

    1. “Cheap Chevy” is never going to be good.

      (My wife’s Volvo has auto-stop, but you can turn it off with a button.

      She hates it; I don’t really care.

      Ref. OP, modern systems are MUCH better than older ones. I know some of them do tricks like stopping with one cylinder at bottom dead center with a fuel charge, letting it start MUCH more easily and with less starter motor (if any).

      Not sure how widespread that is, and of course if you sit for TOO long the fuel settles out and you lose the benefit, but …)

  3. I showed this to my wife. She has a 2021 GLE that had she experienced the auto start/stop before she purchased (we tried, but I think the dealership hid it), then she would not have bought it. It may have one of those starters, because the starter cranks like it is trying to rotate the entire engine, not just the crankshaft. It is violent.

    You can just get a hybrid Acura MDX and it does the same thing as the new Merc.

      1. Mercedes, like other manufacturers, have a button that you can push that disables it, so long as you push it every time you drive the car. I’ll credit Mercedes for putting that button next to (like a crescent moon around) the starter, so that you can start the car and immediately disable that feature. If you forget, the car will provide a violent reminder when it stops and starts later.

        1. Some clever wiring could make that happen on every start, if you’re brave.

          People sell OBD2 modules that you leave plugged in that turn that shit off for you, effectively permanently.

          (My suspicion is that no manufacturers let you DIY turning it off for good, because that might affect how their CAFE numbers are calculated?)

  4. Why would anyone pay for something like this? If you buy a car for $114,000, it could be so crappy that it only got 17 mpg, and you’d still get all of the mileage out of it that a six-sigma driver does by having $30,000 of that price be devoted to buying gasoline at $3 a gallon. And you’d still have an $84,000 freakin’ car!

    There are really nice little airplanes that cost less than $84,000, for goshsakes…

    1. I’ll note my wife’s version of the GLE 350 costs less than $84,000. Still, it doesn’t have some features available in my CRV that barely cost over $30,000 and gets 35mpg without a hybrid. I also purchased the last year in which Honda didn’t include the auto stop/start feature.

    2. “603 hp and 627 lb-ft of torque”.

      That’s why, along with the star on the hood.

      And why nobody cares about 17mpg – the start/stop and all that is to keep up Mercedes’ CAFE numbers and for posturing, not a practical concern to any buyers.

      (AMGs are for people who want to display that they can afford an AMG – or, in the case of the CLA or GLA, display that they don’t realize that a budget AMG isn’t a status symbol.)

      (Yeah, you can get more power for less in a Dodge, but then you’re stuck in a Dodge.)

  5. Our Mazda CX-5 has start stop. Works OK when it actually cuts in which is almost never. In 13000km the screen tells me we’ve saved 11 Km worth of running.
    Seems it is heavily guarded against stopping the engine unless it is up to temperature, interior is at correct set temperature etc.

  6. Apparently, I was 35 years ahead of the curve when I drove my pickup 400 miles with no way to release the clutch. Start in 1st, shift up and down with the throttle. When you had to stop, shut off the engine, shift it into 1st and start again.

    The starter motor held up until I fixed it.

    I’ve been hearing about the carmakers wanting to switch to 48V for 20 years, eventually it will allow electric air conditioning and eliminate all the accessory drives except the alternator. 48V because it’s just below the magic 50V that is “dangerous” voltage instead of “low” voltage.

    The starter on the Prius is the belt drive hybrid motor and the engine is only 1.8l so it’s almost unnoticeable. The EPA circuit includes a lot of start-stop so it probably gets them a couple of phantom MPG.

    My brother knew a guy that was kicked out of a Rolls Royce showroom when he asked about fuel economy, I’d figure the same applies to $100K Mercedes. If you have to worry about how much gas it takes, you can’t afford it. Maybe not, ain’t inflation wonderful.

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