Why does braking gradually and accelerating slowly give a car better gas mileage?

Question

Does this advice apply to all cars?

In: 156

Answer 1

optimal fuel air mixture is lambda=1 (around 14:1 air-fuel mixture)
everytime you accelerate you will enrich the mix with more fuel … lambda <1, meaning the efficiancy gets reduced. when you reduce throttle the mix goes to a lean fuel mix, lambda>1 or nowadays fuel gets completely shut.

So best strategy is to keep acceleration time short and switch to higher gears early.