Why you can’t stop the start-stop feature

Dear Car Talk: I have a 2023 Land Rover Discovery. Like most new cars with internal combustion engines, it has an AutoStart feature that turns the engine off when stopped at lights and turns it back on as you drive off.

I recently saw a survey on an automotive blog. AutoStart was the most disliked feature.

What makes it even worse on the Discovery is that, while you can turn the feature off, it does not stay off, and you have to turn it off every dang time you drive the car.

If they wanted to do so, could the manufacturer push a software update that allows the “off” setting to be retained, so it doesn’t have to be done each time you drive the vehicle?

Tim

Gee, I test drive a lot of cars, Tim. And on a few, like Subarus, you really notice the restart. But on the majority of cars these days, I hardly even notice it. And I don’t remember noticing the restart on the Discovery.

But you do, so let’s answer your question. Yes, they could issue a software update to allow you to turn off the feature permanently, but then their EPA mileage ratings would have to be recalculated.

Almost every new gasoline-powered car now comes with an auto stop-start feature. It’s there for obvious reasons; when you’re stopped in traffic, you’re wasting fuel and creating unnecessary heat and pollution.

Estimates say that these features boost your fuel economy by 3%-5%, which is a meaningful increase.

But if the manufacturer wants to take advantage of that fuel economy increase – for corporate average fuel economy measures or to help convince people to buy the car – the rules say that “start-stop-on” must be the predominant driving mode.

In practical terms, that means that the manufacturer can’t allow the system to be permanently disabled.

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