I finally decided to bite the bullet and fork out for a diesel heater to improve the comfort of my camper van and to extend the useability to colder months. It was booked it in to have an Air Top 2000 ST installed. This is the most compact Webasto heater with a heat output of 2 kW so should keep the inside of my camper well toasty even in the depths of winter. Once the instal was complete I had almost two weeks away, mostly in Scotland and the Isle of Skye in March. The van was comfortably warm throughout despite nights often being frosty, in fact I had to be careful not to set the thermostat too high as the first couple of nights I woke up because I was too hot! The heater has made a huge difference and I would recommend it to anyone wanting to make their camper useable 12 months a year. Hard to tell how much fuel it burns but probably less than a litre a day.