I have a Landcruiser 3.0 turbo diesel 1998 Never go above 2.000 revs which shows on the speedo around 53mph that is the best towing performance for me with diesel around the £1.45p a Litre i get as much as i can out of every Litre. You arrive a little later but who cares you are on holiday. As what has already been said tomany caravaners think they are driving a car with nothing behind them. try stopping in a hurry when you are doing 70mph with around a ton of caravan. You will be supprised how long it takes.