Car Off at Traffic Light?

Speaking of bicycles (I just came from the mall thread), I was out riding mine tonight and the vehicle behind me in traffic in the turn lane had the engine off while waiting for the light to turn green. When it turned green and time to go, the engine was back on. Is this a new thing with newer vehicles or a personal thing?

Stop-start system

Yup.

There was a thread bitching about it not too long ago.

My manual equipped Focus RS has it. It's not bad and only engages when the car is stopped, in neutral and my foot is off the clutch and on the brake. It's easily turned off via a button on the center console.

Yep, we're seeing it more and more on new cars. It's one more way to save a bit of fuel. (Figure you're getting 0 mpg while stopped.)

Is it the worst thing ever? Honestly, it doesn't tweak me too much. On most cars, you can defeat it.

Does it get warm inside since the a/c is off? Usually the engine bumps back on before it gets warm inside the cockpit.

I've heard it on new Audis and Grand Cherokees (I think). I wonder how over-engineered the starters are to deal with so many extra cycles. At least, I hope they are.

Just pretend you're out on the links.

Wife's new ride has it. It will turn back on for climate control reasons. It's pretty quick to react too, just taking your foot of the brake is enough and it's running before you can get your foot to the gas pedal. Unless your a left foot braker I guess. The only time I've had it get annoying is when I have the auto hold turned on. With that on the car will hold itself still at stop light so you don't have to hold the brake, but with the engine stopped and without you pulling your foot of the brake to start the engine it can be a little bit jerky when it reengages. All in all I don't mind it one bit.

In the Mini, it fires up when you go to the clutch for first. If you're in real stop/go it gets annoying listening to it and I shut it off (quick stab of the switch). If conditions mean I might sit a little while after stopping I turn it on (it stays off if turned off, and doesn't turn back on next time you start the car).

I did find it annoying in a rented 328i with auto, as it made for a lurch as I let off the brake and went for the gas with it firing up somewhere in the middle.

Our commute is short, and traffic's been bad lately. Last tank was 20mpg in the Mini with 1.5L triple... Too much stop/go, I guess. Idling really doesn't help mileage.

I have it in a 2016 Volvo XC70. My only complaint is that it turns on by default each trip. The button only turns it off till next time you shut the car off i typically keep it on. It is smart enough to not turn off if toohotor too cold.

I rented a Malibu in L.A. recently that had the stop-start feature. It was mostly innocuous. I liked that I could re-engage the engine by slightly lifting the brake pedal without the vehicle starting to roll. Doing that, the engine would not turn off again until the next stop. Helpful for keeping the air conditioning running.

I had it in a rental a few years ago.

I've heard that with direct-injection engines, they don't have to use the starter. The ECU just injects fuel into a particular cylinder near TDC, fires the spark plug and that restarts the engine. Or something like that.

JeffHarbert wrote: I rented a Malibu in L.A. recently that had the stop-start feature. It was mostly innocuous. I liked that I could re-engage the engine by slightly lifting the brake pedal without the vehicle starting to roll. Doing that, the engine would not turn off again until the next stop. Helpful for keeping the air conditioning running.

Yeah, the parameters require the vehicle to exceed 6mph between stop/start activation. But, if you had the A/C on, it should have stayed on anyways, as A/C Compressor Command Off is another parameter it wants to see before it'll activate the system.

I will say that if you are low on fuel, it will scare the daylights out of you. Was taking one to a fuel station and it was low on gas. Sitting at a stoplight and all of a sudden it kicked off and I thought it was out of gas.

Ian F wrote: I had it in a rental a few years ago. I've heard that with direct-injection engines, they don't have to use the starter. The ECU just injects fuel into a particular cylinder near TDC, fires the spark plug and that restarts the engine. Or something like that.

In theory, that would work. But nobody does it in the field- as it would almost require that the engine stops in a specific location for it to work. So DI engines still use the starter motor.

It is truly astounding the number of features new vehicles are equipped with that I would pay extra not to have.

alfadriver wrote: In theory, that would work. But nobody does it in the field- as it would almost require that the engine stops in a specific location for it to work. So DI engines still use the starter motor.

But in theory, wouldn't the computer be able to stop the engine at a specific location?

Ian F wrote:

alfadriver wrote: In theory, that would work. But nobody does it in the field- as it would almost require that the engine stops in a specific location for it to work. So DI engines still use the starter motor.

But in theory, wouldn't the computer be able to stop the engine at a specific location?

Only if it had a brake to stop the engine exactly when it wanted. Momentum in the rotating assembly means it doesn't stop instantly or 100% consistently.

I think this is going to become pretty standard in the quest for more mpg. I think even some of the new F150s do it, but as noted most vehicles have to meet a specific set od parameters to do it. AC on, tow mode on...there are a ton of things that disable it.

In my daily driving it will save nearly nothing. If I spent 2 hours a day sitting in gridlock (Atlanta, LA, etc) I can see it having a noticeable impact.

It stops the engine with the A/C on. It just starts it again if the interior temp climbs too much.

rslifkin wrote:

Ian F wrote:

alfadriver wrote: In theory, that would work. But nobody does it in the field- as it would almost require that the engine stops in a specific location for it to work. So DI engines still use the starter motor.

But in theory, wouldn't the computer be able to stop the engine at a specific location?

Only if it had a brake to stop the engine exactly when it wanted. Momentum in the rotating assembly means it doesn't stop instantly or 100% consistently.

Exactly. There's also an issue that there are a small percentage of engine stops where the engine will back up a little, too- and that requires a second crank sensor to detect that. And even though the sensor is pretty cheap- given the benefits of know that are so very small- it's just not worth it.

A precise engine braking system would be pretty expensive (relatively speaking).

ultraclyde wrote: I think this is going to become pretty standard in the quest for more mpg. I think even some of the new F150s do it, but as noted most vehicles have to meet a specific set od parameters to do it. AC on, tow mode on...there are a ton of things that disable it. In my daily driving it will save nearly nothing. If I spent 2 hours a day sitting in gridlock (Atlanta, LA, etc) I can see it having a noticeable impact.

Just like every technology, how it's used by the owner will greatly effect it's bonus. For many years, hybrids didn't help much on the highway- but got a HUGE bonus in stop and go driving.

But the average of the fleet will show a benefit.

Toebra wrote: It is truly astounding the number of features new vehicles are equipped with that I would pay extra not to have.

Porsche has been killing it with that sales model for decades. Starting with cars like the RS America. Take a basic Carrera 2, add no radio, no leather, no AC, paper door cards, and some logos... (huge cheesy wing notwithstanding) and sell for a whopping premium over base Carrera 2!

I had it in a rental diesel manual Fiat Tipo wagon (wonderful car!) while in France. I didn't know it was there so the first time it when off I thought the car had stalled. Happened to be in a toll booth trying to figure out how to pay a toll in French and bam the engine quits...somewhat stressful. It worked OK for the most part, but I found that I had to delay lifting the clutch for a second or two to give the engine time to spin up, otherwise it would stall or stumble badly. I never figured out how to shut it off, but if I left the clutch in while stopped the engine always stayed running.

In my hybrid the engine start/stop is seamless. I think the battery power gets you rolling and the engine doesn't need to do any work for enough time so that it can start smoothly.

Huckleberry wrote:

Toebra wrote: It is truly astounding the number of features new vehicles are equipped with that I would pay extra not to have.

Porsche has been killing it with that sales model for decades. Starting with cars like the RS America. Take a basic Carrera 2, add no radio, no leather, no AC, paper door cards, and some logos... (huge cheesy wing notwithstanding) and sell for a whopping premium over base Carrera 2!

While that may work for Porsche, there are very few car lines out there that stripping the car down to a bare minimum would result in a higher price to pay for the car.

For sure, a basic, un-optioned sedan would never, ever, be more expensive than the top optioned model.

For that matter, most cars do have a super basic option, which is cheap. If more here bought new cars, it may actually be significant.

For every 10 Fusions Ford sells with auto start-stop, the increased CAFE sustains another F150 sale?

Lots of new technology that you're not really paying to have per se. The cost of new cars, adjusted for inflation, is about flat.

In reply to Tyler H:

Not really- a few years ago, the calculation for fuel economy was more based on the individual vehicle. So Fusion sales don't change the F150 fuel economy targets.

Which now has translated to the F150 now having start-stop.