Hopefully a few readers are still with us, and possibly some previously uncommitted to eco-driving previously took up the challenge of tackling a familiar, busy, stressful, urban route using the minimal aggression approach we suggested, before the country entered lockdown. Hopefully the results were also encouraging. But with the very best of intentions, you need a clear appreciation of what mostly influences your fuel consumption, in terms of engine efficiency, your speed, and the power you use. More power means more energy, and more fuel consumed, and the key is not to waste that power. On clear roads, success often comes down to controlling your speed, knowing how to use your gears, and giving yourself enough time to complete any journey at an economical speed. On busier roads, though, much depends on reacting appropriately to the events around you and anticipating the actions of other drivers. If you allow them, they will force you into doing things that you want to avoid and deny you the freedom to drive as you want, at the speed you desire. Don’t let tailgating racers behind bully you into going at a faster pace than you would otherwise like. They often get fed up when you don’t speed up, so make it easy for them to overtake, and you’ll likely coast up right behind them at the next set of traffic lights!
More than perhaps anything else though, you need to avoid unnecessary hard acceleration, using uneconomically high engine speeds, and the hard braking that often follows. Let’s stop, though, and make another important point. You should accelerate from lower speeds and up to cruising speed positively, using your engine to its best efficiency. Changing up early into the next gear hoping for better fuel economy does not work. Learn your engine’s characteristics, know the best speed band around its peak torque rpm, and accelerate firmly through the gears with that in mind, dropping into the next ratio around the peak torque rpm figure. Then drop into a high gear when you hit your cruising speed and hold it on a light throttle, as near to peak torque engine speed as possible.
Choosing a cruising speed on any road is not always in your hands, though. Often on the motorways, you can find that cruising around 60 to 65mph is bad news, as it’s too close to the cruising speed of many commercial vehicles. You’ll spend too much time and waste fuel accelerating and braking to avoid them, as they weave in and out of the two inner lanes, and not always signalling their intentions. It is better to speed up to 70mph, where what you lose in added wind resistance and the need for more engine power, you’ll gain by being able to hold steady cruising speeds. But it’s a variable target, and on multi-lane roads like the M25, you’ll likely have a choice of lanes, when the quietest one, where you’ll be least impeded, is often the best bet. Also bear in mind that there’s a huge amount of turbulence behind big commercial vehicles, which adds significantly to your air resistance. So, don’t drive close up behind them, if you can possibly avoid it.
Here are a few other “dos and don’ts” that apply in nearly all open road situations. Always keep a keen eye on the road 100 yards or more ahead of you, and lift off the right pedal early when you see red brake lights or queuing traffic – resist the urge to brake. You’ll be surprised just how far your car will roll without using any fuel being used, particularly if you’ve taken advantage of the economy gains of low rolling resistance tyres that cost little or no more than ordinary rubber. They can save you as much as one gallon of fuel in twenty. Roundabouts are a classic situation where, by looking well ahead, you can save losing momentum by coasting towards them without braking, and then braking lightly or even accelerating, to feed safely into a gap, without any need to stop.
Above all, though, look on this kind of driving as a challenge, and you’ll enjoy it far more than you might think. There’s a new purpose behind every journey that’s far more useful than just trying to get somewhere in the minimum time by setting off as late as you can. As many will vouch, you may lose barely any time, and surprise yourself with just how economical your car can operate at.