Ways to save at the pumps
RUNNING ON FUMES? AT R22/L OF FUEL, MANY DRIVERS ARE FEELING THE PRESSURE
Use your onboard computer to watch your consumption.
You don’t expect good fuel economy from a 6.0-litre V12-engine supercar. But, even so, after a morning and a few afternoon hours with an Aston Martin DB9, I had still to look twice at the trip computer: 24.9 litres per 100 kilometre.
In two decades of testing and writing about cars, that is the worst I have seen. The best was over a 2 000km trip in a Ford Fiesta 1.5 diesel a few years ago, when the overall average was 4.0l/100km. Honourable mention for a VW Jetta 2.0 TDi which, on a 4000km+ round trip to Knysna returned an overall average of 4.7l/100km.
Fuel consumption figures will have been on the minds of most motorists recently as the price soared past R22 per litre for both petrol and diesel. Welcome, then, to my world of fuel economy…
When I first started driving, the family Datsun 1200 did not have a trip meter (not surprising, considering it was a 1971 model). On holiday once, I did use a paper graph fuel consumption plotter (handed out as a freebie when we filled up somewhere) to calculate how much we were using. It ranged from 30 miles per gallon (about 9l/100km) to about 43mpg (just on 6l/100km), avoiding every spietkop…
When I first bought my own cars, I seldom worried about fuel consumption … fuel was cheap (even comparatively speaking) and working out numbers would require pen and paper). Once I got into the habit of fully filling the tank, rather than topping up, and resetting trip meters, I began to regularly keep an eye on consumption.
Our trusty VW Jetta, which served us for a quarter of a century and 350 000km, gave consumption of just under 10l/100km in the city and just below 8l/100km on the open road. These days my 18-year-old Subaru Forester returns around 7.9l/100km on a long journey and my wife’s six-year-old Forester goes into the low sevens easily on the open road.
With test cars, even the fast ones, I find myself keeping an
eye on the trip computer, rather than the rev counter as I used to do in my wild and woolly days. Most trip computers these days will show instantaneous consumption – either in numbers or graphics – so you can keep track of how you are doing.
And, trust me, once you are into it, trying to keep your average going down as your range goes higher can become quite addictive.
Although I am by no means a “hypermiler” – the person who wrings every last bit of useful effort out of every last drop of fuel to go further on the same amount – I will go toe to toe with most (other than fuel economy run specialists) and better their results.
Here are some ideas you can use (or not, up to you), to help improve your consumption:
1 Buy a fuel-efficient car. Something like a petrol Suzuki Swift, for example. The Swift’s engines are some of the most economical currently on the market. Diesel vehicles are more efficient overall than petrol ones, although that gap is closing as technology improves. Also, diesel has been getting an under-served bad reputation as being “dirty” and it will soon become difficult to find diesel in small or medium car applications … although diesel is far from dead when it comes to double cabs and SUVs.
2 Service and maintenance will pay for itself through reduced fuel consumption.
3 Keep tyres correctly inflated. I sometimes add a bit more if I am trying for extra economy, because harder tyres mean lower rolling resistance and less power is needed to go the same distance. Do not overdo tyre pressures, because having them too high affects handling and can lead to blow-outs on exceptionally hot days or at high speeds.
4 Coast whenever you can. This is controversial, but I have proved it time and again with manual cars. Pop the gearbox into neutral on long downhills and re-engage drive again on the upslope. I know this is frowned upon by traditionalists because it allegedly makes the car difficult to control. No it doesn’t, if you are a competent driver. There are those who point to the fact that modern, fuel-injected engines consume no fuel when the accelerator is not used and therefore you would be using more fuel in neutral because the engine is still consuming. That disregards the reality of mechanical drag. I have tested fuel-injection cars on long downhills – even though a car left in gear apparently consumes no fuel, mechanical drag slows it down; in neutral, a car accelerates going downhill. So, left in gear, more fuel will be needed to recover the lost momentum
5 Don’t use cruise control. This is another common fallacy: that computer brains are better than human ones at saving fuel. A cruise control is programmed to maintain a certain speed – up hill and down dale. And more power will be used (and therefore fuel) when the speed drops below where it should be. Conversely, a manually controlled car will see a driver allowing speed to reduce slightly on up hills and recover on the downhills, without excessive use of the throttle.
6 Read the road. Look ahead. If there are brake lights coming on half a kilometre up the road, know you’re going to have to slow down and come off the gas. It will save your brakes, too. Drive smoothly, accelerate gradually and steadily and don’t brake harshly.
7 Finally, pay attention to your trip recorder. It is your friend. Paying attention to how you drive will actually pay real-world, real-wallet dividends, not to mention being kinder to the planet, its atmosphere and finite resources.
And you should probably think twice about that Aston Martin DB9…