Your correspondents ask about the relative fuel consumption of cruise control versus manual driving. I have recently driven three return journeys from Cambridgeshire to South Devon, in my Honda Accord 2.4 automatic, travelling at the legal speed limit. Each single journey was 266 miles, and all six journeys were completed in times within five minutes. All but seven miles of each journey involved travel on either major A roads (A14, A380) or motorways (M6, M42, M5). I drove to Devon with me controlling the speed, and returned using cruise control. According to the car’s computer, I achieved 41.7mpg and cruise control returned 37.5. That would indicate that cruise control can use approximately 10 per cent more fuel. But of course, you do drive ‘down’ to the West Country and ‘up’ to London.