91.1 mpg in real life
On the 100 mile journey from Silverstone to his home in Surrey, along a lot of motorway and some large altitude changing country roads, Will managed a whopping 91.1mpg average in a VW Polo Bluemotion. A simple economical 1.4 litre turbo diesel engine in a small car means that it is under the magic 100gCO2 per km which means no congestion charging (and I think no road tax). It has skinny tyres, a slicker aerodynamic profile and long gear ratios. Frankly it whips the silly Toyota Prius. Our figure could actually have been even higher had we not got stuck in some of the usual M25 traffic. We had achieved 95mpg from the motorway journey before we hit the country roads.
The main tips are:
Get to 55mph and top gear as soon as possible. Keep it at 55mph. At all other speeds, be in the right gear for the speed you are travelling at.
Slipstream lorries - they cruise at around 55mph (avoid fast coaches) and they punch a nice hole in the air for you to tag along. Try following oil tankers as this will require a combination of both skill and bravery! We saw an average of about 120-130mpg behind a lorry. If you're worried, you can keep your left foot over the brake pedal just in case.
Allow the car to gently build up speed on downhill sections and keep it in the same position everywhere else.
Keep the a/c off and windows closed. This may require you to wear fewer clothes and drink cold water. You may only open windows when you are braking. Will particularly enjoyed the aero braking element of putting his hand out of the window. You may only use A/C to increase engine braking in cases you would have applied the brakes.
Carry speed through corners - this must be balanced with acceptable tyre wear, as tyres have very high embodied energies.
Acclerate Gently: only depress the accelerator enough for gentle progress.
By doing this, one 40 litre tank of fuel could have a range of 950 miles!! Maybe this could be used as a new government incentive to keep the kids driving slowly: cash payouts for high fuel economy?
Fuel Consumption Average: 91.1 mpg (imperial) or 3.10 litres per 100km
Peak Fuel Consumption: 182.0 mpg
Average Speed: 41 mph
Peak Speed: 67 mph