Does stop-start technology really save fuel?

I have a new Mercedes with an 'Eco' button, which cuts out the engine when stationary to save fuel. Surely turning the engine on and off engine wastes more fuel then just idling briefly?

Asked on 17 June 2013 by NFB

Answered by Honest John
Not once the engine is hot. But it can be very irritating. The Mazda 6 Skyactiv with i-eloop has by far the best stop start system.
Similar questions
I have some doubts about the benefit of this facility. Every time I come to a stop with foot held on the brake the engine stops and release the brake and the engine fires up. This means that the battery...
I've found a route to work that is quicker, quieter and less miles. On the motorway it's 18 miles, through the town and stop/start at lights (although very quiet at that time of the morning) its only 10.5...
The brochure for my car says combined fuel consumption is 67.3mpg with Start-Stop and about 62.0 without Start-Stop. I can only achieve 57.6mpg so, as you can imagine, I am struggling to better this and...
Related models
Nimble and agile handling. Spacious cabin is very well made. Huge improvements to refinement and steering from October 2016.
 

Value my car

Save £75 on Warranty using code HJ75

with MotorEasy

Get a warranty quote

Save 12% on GAP Insurance

Use HJ21 to save on an ALA policy

See offer