Quick replies 2907

I need help. I'm driving a 1993 BMW E36 320i and I would like to know why it is so heavy on fuel. Some of my friends are driving the same model, but they don't have that problem. - Steve

Steve, it's very difficult to make valid pronouncements on fuel consumption without a careful study of all the factors involved.

How accurate are your figures? How accurate are the figures supplied by your friends? Do you have comparable usage patterns?

Even to find a figure for what you can reasonably expect is difficult, but using road test figures obtained by CAR magazine, I'd say anything between 9 and 12 litres/100km has to be regarded as acceptable.

If the car is using more than 12 litres/100km, you should start looking at the classical factors affecting fuel consumption, with driving habits and the engine's state of tune being at the forefront.

On new cars the fuel consumption, measured by the Euro cycle, is given by a sticker on the windscreen. While this may not be a realistic figure, it does provide a basis for comparing the consumption of different cars.

SUBSEQUENT to our article about wiring harness problems on certain C-Class Mercedes models from the 90s ("A solution to electrical woes", Motor Mania, July1), we received a letter from a reader with a 1996 280E Mercedes, asking whether the problems were confined to the C-Class, or have also been reported on E-Class models.

My enquiries at two local auto-electricians revealed that unfortunately the same problem (disintegrating insulation) has also been found on E-Class models.

The reader then took his car to a nearby Mercedes dealership for the harness to be inspected, and, to his relief, it received a clean bill of health.

Other readers should consider following his example. It may save them much frustration as well as the damage that can result from short circuits in the wiring.

Of course, it would have been nice if Mercedes could have come clean and told us exactly which cars are vulnerable, but I suppose it will lay them open to astronomical claims for compensation.