2011 Green Grand Prix, SilverstoneEnlarge Photo
Earlier this month, we attended an event at the Stowe circuit at Silverstone Race Course dedicated to greener driving. Setup to reward green driving styles and drivers who got high gas mileage throughout the day, the driver named official 2011 Green Grand Prix champion had never even driven a green car before the event.
But while many taking part had never set foot inside a green car, we used the day to see what tips professional race-driving instructors could offer to help us improve our green driving style.
At the end of the day it left us with a surprise conclusion: driving economically isn’t just about knowing how to hyper-mile. It’s about knowing how your car inside out.
Know the accelerator
Over the course of the day, we drove everything from clean diesel stop/start cars through to pure electric cars.
And switching between them rapidly, we noticed that each car had a very different feel to the accelerator pedal. Normally, when focusing on speed rather than efficiency, that’s not a problem. But when smooth, fuel-efficient driving is the goal, switching to an unknown car is particularly difficult.
Know what happens when you lift off
Similar to knowing how much input you need to get your car moving away smoothly without wasting energy or holding up traffic, knowing what happens when you lift off the accelerator is just as important.
For example, electric cars generally mimic engine braking when you lift off the accelerator, using regenerative braking to slow the car down. But not every car uses the same amount of regenerative braking. Take the 2009 Mini E or 2010 Tesla Roadster Sport 2.5. With practice, lifting off the accelerator in either car early enough can almost bring the car to a standstill without using friction brakes.
But get in a 2011 Smart ForTwo Electric Drive, and you’ll find that lifting off has less of a dramatic effect on car speed, meaning you can lift off the accelerator earlier for the same stop-sign.
Know what speed your car’s engine is happiest at
Switching between cars of various fuel types and technologies so quickly, we also noticed that knowing where the engine was most efficient changed from car to car.
For example, a large clean diesel engine will be most efficient at a completely different engine speed to a small four-cylinder gasoline engine. It’s no good assuming every engine is equally as economical at a certain engine speed.
This is especially important if you drive a car that gives you some control of which gear you’re in -- like a manual stick shift or semi-automatic paddle-shift system.
Once you know where your car is most efficient, you can use the car’s tachometer (rev counter) to help you get the best gas mileage.
RAC Green Grand Prix 2011Enlarge Photo
Know what happens when you brake
Just like knowing the accelerator response, knowing what happens when you brake can really help your fuel efficiency.
For example, stop/start cars may turn off the engine completely when you brake, allowing you to coast to a stop on friction brakes, while hybrids and electric cars may use regenerative braking to slow the car down if you use light braking force.
But try to brake in a conventional car as you would in a hybrid or electric car, and you’ll find that there’s little or no gain to gas mileage.
While smooth and gentle acceleration, reading the road ahead, knowing your route and making sure your car is properly maintained can really help you achieve good gas mileage, learning the quirks of your own car can really help you turn good gas mileage into awesome gas mileage.
And the best way to learn your car’s quirks? Take it for a drive on a day when you don’t have to be anywhere in a hurry. Make sure you choose a route with plenty of different types of roads, from city streets through to rural routes.
Play with different acceleration and deceleration. Learn how your car handles, and just how fast it feels comfortable going into a corner.
Know your car better, and you’ll get better gas mileage.