How does a stop-start engine systems work?

We have a Ford Fiesta with a manual transmission. Could you explain how the stop-start operates?

Asked on 20 September 2021 by Andrew Maccall

Answered by Russell Campbell
Stop-start engages when the car stops and you put your foot on the clutch – it turns the engine off when you're stationary and switches it back on when you re-engage the clutch. It is designed to save fuel and tailpipe emissions that would otherwise be burnt when the car is idling (at traffic lights, for example).

It only works when it's efficient to do so, though, usually it'll be inactive as the car warms up, to help it reach its optimum running temperature as quickly as possible. Other strains on the engine might stop stop-start operating, such as having the air-conditioning running on a hot day.
Tags: stop-start
Similar questions
I have just bought a Ford Fiesta Zetec with a 1.0 petrol engine and 80PS. I am really happy with the car, but am concerned that the stop/start system will put excessive wear on the starter motor. As...
My Fiesta with EcoBoost 100 averaged 48.5mpg on one long journey, while the on-board computer shows 37.4mpg overall, mostly on short local trips along fairly congested roads in suburban London. May I suggest...
My 2018 Citroen C3 only does short journeys on average, say, 10 -15 miles. With the advent of the recent colder weather, the stop-start no longer operates at traffic lights and elsewhere. Any information...
Related models
Sharper look for the updated Fiesta. Comes with Ford's award winning 1.0 EcoBoost three-cylinder.

Value my car