Good to see the DM being asked a question and getting experts to answer it. The report concluded that the additional energy required for the engine to repeatedly accelerate up to a 30mph speed limit in stop–start driving means 20mph zones are generally more fuel–efficient.
Does my car use more fuel at 20mph than at 30mph?I live in North London, where roads now have a 20mph limit - and I'm convinced that I'm filling up with fuel more often.www.dailymail.com