Incredible how carrying a heavy load can affect mpg. Yesterday I loaded the X5 with 300kg of wood chips for my burner – the best I could achieve was 23mpg.

That’s quite a lot of chips but considering this hybrid Beemer is meant to top out at 85.6mpg, I was unpleasantly surprised.

The 111bhp electric motor was no use in this situation, the X5 was suddenly too heavy for anything but the 2.0-litre petrol engine which had to kick in – and it struggled.

Minus the wood chips, the X5 is a smooth and elegant drive. Power take-up can snatch under harsh acceleration and it also eats into the stored battery power.

So far I’ve experienced nothing in this car to tempt me away from the diesel…