Hi mike in all fairness on the motorway faster roads at those speeds you would only be using the petrol engine as the hybrid system does not engage at speed., around towns and villages Under thirty the electric hybrid works best but you still have to be gentle as the petrol cuts in .in reality this is seamless and hardly noticeable.as for economy when I said mid fourtys mpg this is easily achieved and what hybrids give you is almost diesel economy from a petrol car ,I am being objective the car was excellent over three years and did everything really well