Motoring corner: Improving your fuel Economy

How do you drive? Do you zoom away from the traffic lights? If so, you are wasting petrol and your mpg will be down. If you’re endurance racing at 120kph on the motorway, you are wasting petrol.

Saturday, March 03, 2012

How do you drive? Do you zoom away from the traffic lights? If so, you are wasting petrol and your mpg will be down. If you’re endurance racing at 120kph on the motorway, you are wasting petrol.

Here’s the thing your petrol mileage can drop off as much as 15% between driving at or below 100kph and driving above 100kph. Now If you love speed as much as the next person but you have to be realistic here, do you want better fuel economy or to get there quicker? This sounds funny but what I am telling you is that, driving slower absolutely will improve your mpg. Why? Because once you get over about 100kph, you’re using more engine power to overcome drag, which means consuming more petrol to do it.What about when you’re not on the motorway? Well consider a little less braking if you can. If you can see the next set of lights ahead of you are red, don’t race up to them and come to a complete stop. Try to moderate your speed a little if you can do it safely. If you can get there as they turn green and the traffic in front begins to move, you’re doing OK. That’s because it takes more energy to get you going from a complete stop than it does from a slow roll. So if you can do this, it will improve your mpg.Many of us drive around with medium or premium petrol in our tank when we just don’t need to. If your owner’s manual says "regular”, it means it. Putting mid-grade or premium in is just wasting money. Why? Unless you have a high-compression engine which could be prone to detonation (pinking / pinging), you have absolutely no need for high-octane petrol. The only thing that higher octane gives you is less probability of detonation. In high-performance cars with high-compression engines that means allowing the engine management system to work at peak efficiency but for probably 75% of you, your car will quite happily run on the cheapest petrol you can put in it. Not an improvement in fuel economy per se, but money saving at least.  Consuming the so called Extra this or that is just a gimmick by the Petrol companies to subject you to consuming highly priced products in the guise of getting better this or that!Getting rid of the roof racks can greatly improve your MPG.  When you’re commuting to work, that empty roof rack is adding aerodynamic drag to your car. More drag means more power to overcome it, which means worse mpg. Take it off when you’re not using it. Same goes for those ‘aerodynamic’ roof boxes - if you’re not using it, get rid of it. Yes they look aerodynamic but the fact of the matter is they do induce drag. And to be honest, they look silly. Hey - I know it means getting up and doing something rather than just routinely getting in your car and driving off but we’re talking about fuel mileage here. Fuel economy, it’s all to do with money. Realistically, if you religiously stick to the above points, you should expect to see an mpg improvement of about 15%. A 15% improvement in fuel mileage correlates to a 15% decrease in outlay to fill my car. And so on and so on. So you can keep wasting money if you like, but if you’re serious about getting better fuel mileage, these simple steps really will help. Happy motoring and I hope you see some improvements in your fuel economy.