Guys a note on Fuel economy ! Remember in the winter your lights are on more, your heater blower is on more, your front and rear heated windscreens and mirror heaters and possibly heated seats are on more. The power for all this comes from the engine and therefore consumes extra fuel to do this. Also it is cold and therefore you may be running in a lower gear more often to warm the engine up quicker. And more importantly your basic driving habits change and this has an even greater impact on fuel economy. All these are going to impact on economy more than the booster heater. p.s. slightly of topic, Automatics tend to get better fuel economy than Manuals. Yes this is true as drivers of automatics tend to drive more sedately than manual drivers ( with the odd exception, you know who you are ! )