Look at the photo, and beyond me and the car in front, is a Rolls-Royce Griffon Engine; a 37 litre V12 as fitted to the Shackleton maritime patrol aircraft. This stationary engine and propeller formed a twin display with a Rolls-Royce Merlin engine; a 27 litre V12 as fitted to the Spitfire. When both were running at full power the noise was tremendous and the ground shook with the power of 64 litres consuming 2 gallons of fuel every minute.
My fuel consumption isn’t quite that bad, but on the journey to Rougham Neil stopped at the local Shell garage for some of my favourite V-Power fuel. I noticed they were still flying banners for their new standard petrol, FuelSave, which was launched recently. Shell are claiming the equivalent of ‘up to’ an extra litre per tank (a 2% saving on their figures) due to using new detergents and a new ‘efficiency improver’ that shell claims ‘lubricates where normal engine oils can’t’. Shell will have terabytes of statistics to back up their claims and I’m sure there must be some improvement in fuel efficiency, but I‘m skeptical about the extent of their claims for 2 reasons.
Firstly, their claims for saving an extra 1 litre of fuel per tank are based on a minimum fill of 50 litres. Now, if you have a Shell Drivers’ Club card, you will know that the bonus vouchers you receive are based on a fill of 30 litres. The question is, why don’t they have a standard fill? The cynic would suggest they could only claim savings of an extra litre of fuel per tank if they stretched their definition of a tank by 60%.
Secondly, the new FuelSave campaign coincided with the start of the school summer holidays. Now, because I don’t drive with Neil every day, I asked his Citroen XM (only a 3.0 V6) who is happy on Shell’s standard fuel and therefore has been consuming FuelSave unleaded by default, whether his average fuel consumption had improved; and it had – by 1.5 miles per gallon (actually a 5% increase). Now, back to the school holiday connection; traffic is clearer, no jams and commute times have been cut by a third - a recipe for decreasing fuel consumption if ever I heard one. The question is, how much of this is attributable to Fuelsave and how much to a sudden lack of traffic?