I recently bought a new vehicle and decided to buy an additional maintenance plan for up to 120 000 km. During the first month, I frequently tested the fuel consumption of the vehicle and could never achieve the claimed figure. It was always heavier on diesel.
I then started to compare the speed of the vehicle against my GPS. At 100 km/h on my GPS, the speedo showed about 115 km/h. I realise that this way of comparing might not be the best, but I still came to the conclusion that, if my speedometer showed that I was driving 115 km/h, my vehicle picks up kilometres that I never drove since I was actually travelling at 100 km/h.
The price of a new vehicle depends on the CO2 burden it carries, and the higher the fuel consumption, the more tax you pay. Is there enough control over manufacturers’ claims of fuel consumption?
If I buy a car with a service/maintenance plan, the odometer must in some way be certified to be correct according to certain guidelines. To be out by 15 per cent means that I may lose out on two services that I’ve already paid for if my vehicle is to be serviced every 10 000 km. What is CAR’s opinion on this matter?
FRANCOIS VAN ZYL – By email
There’s a good chance that your fuel consumption is normal because manufacturers’ claims are for the most part based on the European NEDC cycle which incorporates mainly slow-speed driving, as shown on page 141 in the September 2011 issue of CAR. There is no SA government check on the figures supplied by the manufacturers.
Most manufacturers try to ensure that the speedo is no more than ten per cent fast, but it is important to realise that tyre brand, wear and pressure all affect the speedo reading. The 15 per cent you measured is thus fairly unusual. This does not mean that the odometer, which measures the distance travelled, is so far out, because the odometer is driven mechanically while the speedo is driven magnetically. CAR checks both these instruments when we conduct a road test and publishes the data in the specifications panel. We usually find that the odometer is less than one per cent out, so you will not lose any services.