The renowned motoring journalist LJK Setright was famous for his speedy driving. He could also drive as if every drop of petrol mattered. Here’s how he demonstrated the fuel efficiency of the 1976 VW Polo.
“Unless you have tried it, you can have no idea how acutely embarrassing it is to employ this ultimate economy driving technique on roads bearing normal traffic.” This meant accelerating down hills but not up the hills, keeping throttle openings small and constant. He was borrowing a method known as squirt-and-coast. In this method you keep the throttle open at the maximum economical speed, coast down and accelerate again.
That method is fine for level roads, reported Setright. On hills more fuel is used accelerating up hills than accelerating down. The next question is what is that optimum speed? Setright calculated this as “for most kinds of vehicles on most kind of roads (motorways constitute a most important exception) the average speed is about two-thirds of the normally attained maximum speed.” For the Polo this meant driving at about 30 to 33 miles per hour.
Here is how it pans out: “Up long hills it requires great stubborness to keep the pedal steady and allow the car to crawl up as slowly as it comfortably can in top gear, while other vehicles fume in your wake. Going down them, with the speed building up to 45 or 50 mph before the next spell of coasting.” If speeds ever reached 60, Setright could slip the gear into neutral on an uphill section. In all he used the brake pedal three times in 90 minutes.
The reason for all this was that Setright had challenged motoring writer Graham Macbeth to an open-road economy duel in VW Polos. At the end of the duel, when the car ran out of its single gallon of petrol Setright had covered 85.7 miles. Macbeth managed 84 miles. The test showed what was possible with a vehicle he considered a paragon among small cars.
Today, Autocar says of the current BlueMotion 1.2 diesel: ” The official average fuel economy of 80.7mpg is impressive, too – although you’ll be doing well to better 70mpg in the real world.” Carbuyer rates the 1.0 litre petrol as getting 60.1 mpg. It’s worth noting that these figures don’t assume going at 30 miles per hour, closing the windows and turning off the fan.