30.8mpg – I thought I was seeing things! The RX 450H may be super refined and comfortable but I imagined that bolting two electric motors to the V6 petrol engine might also boost economy.

Not so, it seems. In fact, quite how Lexus achieved the official 44.8mpg figure is a mystery. I’ve been on a big economy drive today, treating the accelerator pedal with the utmost respect. However, it appears to have made no difference to my mpg figure at all.

I accept that the 145g/km emissions is exceptionally good for a big SUV but it’s really no better at the fuel pump than the Range Rover Sport we tested two weeks ago.

This might make you question why you would buy a 450h in the first place. Yes you save £120 per annum in road tax over other diesel SUVs. Yes you get a feel-good ‘Hybrid’ badge on the side but is that enough for your £50,000?