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Comment by hbarka | Hacker News Reader

I know right. It’s one of those mysteries. Maybe they thought it saved gas, like in the old days when great grandpa would deliberately stop the engine at intersections. (Which by the way is common now in some modern cars and startles me.)

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Automatic start-stop features do save a meaningful amount of fuel. This article [1] cites about 8% in heavy traffic.

[1] https://www.roadandtrack.com/new-cars/car-technology/a229943...

Emissions from restarting can be higher or lower than idling [1]

• Idling for more than 10 seconds uses more fuel and emits more CO2 than engine restarting.

• Idling fuel usage varies from 0.2 to 0.5 gal/h for passenger vehicles across a range of sizes, and increased with idling speed.

• NOx and THC emissions from restarting are larger, but at least an order of magnitude lower than those from starting a cold engine.

• For short stops, it makes sense to turn the vehicle off in order to minimize fuel use and CO2 emissions. At least for the conditions evaluated in this work, the penalty in terms of criteria pollutant emissions

[1] https://afdc.energy.gov/files/u/publication/which_is_greener...

Oh, is this an automatic "feature" ? That explains what I've been seeing.

And with a lot of cars having turbos, which introduce a noticeable lag (especially as the cars get older - it seems to be inevitable), now you have an additional lag with the auto-stop/start.

Turbo lag isn't increased by start/stop. Start/stop may delay the initial acceleration but from then on, any turbo lag would be the same regardless of the state of the engine before initial acceleration.

That's what I mean. I stay away from dieselturbos etc due to the lag. And now they add another lag on top of that. Bring on electric.

Yeah I hate turbo lag (it was awful on my old Tiguan). Start/Stop worked fine though - not once did I feel like the engine wasn't ready to go after letting go of the brake. I drive super safe these days though so it's not like I was jumping from pedal to pedal.

I have an EV now (id.4) and I'm of two minds. The acceleration is awesome but the inability to do a full road trip is (mildly) limiting and the suspension/drive quality is middling at best (partly because it's an SUV, partly because of the weight).

I'm in South Africa and the country isn't exactly ready for electric cars yet, so I went for a pragmatic choice instead; Toyota Land Cruiser with huge petrol engine. Yes, it costs tons to fill up, but it's not a car you just toss away as it lasts forever. There's also something to be said about longevity when considering the environment.

Land Cruiser/Prado is the car to have! I used to live in Kenya and that was the dream car (had a Rav4 which did the job but was no Prado). I do still have fond memories of my little manual Mitsubishi Pajero Mini:

https://en.wikipedia.org/wiki/Mitsubishi_Pajero_Mini

I don't like that feature very much since it basically introduces a lag.

While I didn't like the start/stop feature when I had a hire car briefly, I can't see how it would ever add a lag. By the time you have pressed the clutch pedal down to put it in gear, it has started.

Most cars in the US are automatics, and it does introduce a lag. I turn it off the moment I turn on the car.

It caused me to almost have an accident when I was in stop and go traffic, specifically because of the lag. The person behind me did not expect me to start so slowly right after stopping (I had to wait for the engine shutoff and then to turn back on).

I've had rental cars where it had an annoying lag and every start felt like a start from cold (ra-ta-ta-ta-voom), but in my current car there is no lag, by the time I've lifted the brake the engine is ready to go. An auto-stop start is also much quieter than starting from zero. I'm not sure what it's doing - this car has an ISG (integrated starter-generator), I'm not sure if that's the difference.

What car is this? Seems like they are making improvements in this technology, then.

It's a 2016 Suzuki Spacia, just a cheap kei car, nothing fancy.

Nobody uses manuals anymore unless you are a driving an enthusiast car like Toyota GT86 etc

Um, what? Last time I saw an automatic, or heard of a friend driving one, was 2004.

Also, s/anymore/any more/

Where is this? Most of the world today uses automatics, I think. Or are you thinking of electric without gearboxes?

It doesn't introduce lag. At least not in a manual car. By the time you've pressed the clutch down and selected a gear the engine will be ready. You can completely forget about it. If you're talking about automatics then maybe you should get a manual if you are so concerned about lag. Engine start/stop might just be your first "don't like it because it's different" thing.

A manual has the same lag, except you're coving it up by adding clutch lag instead.

The clutch lag is there regardless of the auto stop/start, so adding auto stop/start does not introduce any additional lag.

Exactly. That’s what I said.

Not really. The start/stop system is only activated when the car is put into neutral. This is completely the driver's choice. Most drivers will shift into neutral when they anticipate a longer stop (like when they've just seen the light change red or they've pulled over to take a phone call) and then shift back into gear when they anticipate movement. It's rare to be caught "out of gear" and would generally only happen when the driver isn't paying attention. Nobody shifts into neutral every time the car comes to a complete stop like at a give way sign or in a queue.

In the US only 2.4% of cars are manual mostly driven by enthusiasts.

> If you're talking about automatics then maybe you should get a manual if you are so concerned about lag.

I agree with the rest of your comment, but this seems disconnected from any reasonably modern automatic transmission vehicle I’ve seen. The torque converter is never really fully disengaged, so there isn’t lag from a stop to a creep, compared to in a manual transmission which is generally disengaged and covers up the start-stop lag during engagement.

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