A roof carrier will create extra drag even when unladen, resulting in larger fuel bills.

Poor consumption could be due to one of the following reasons:

1. You've been listening to somebody bragging about your model's consumption and there is, in fact, nothing wrong with your car.

2. The engine needs a good tune-up. If it pulls strongly, idles smoothly at the correct speed and starts easily, then there can't be much wrong with it. On the other hand, if it misbehaves in any way, this will usually show up in a worsening fuel consumption, and a good
service should set matters right.

3. The brakes may be binding. This can be checked by stopping
on a slight incline and seeing if the car will run forward when you release the brakes. If it doesn't run forward the most likely reason is a binding handbrake, or rear drum brakes. Disc brakes often make a slight scraping sound when coasting, which is normal.

4. The wheel alignment may be out, and on modern front-wheel drive cars the rear wheels also have to be set, in many cases. This can be checked by inspecting the tyres for abnormal wear patterns, as discussed elsewhere in this booklet.

5. The tyres may be running soft, ie the pressures are too low. This will show up as an unworn strip in the centre of the tread area.

6. Other drag-inducing elements are roof carriers, even when they're unladen, and aftermarket spoilers.

7. There may be a fuel leak in the line, either underneath the car or under the bonnet. Look at your garage floor after you've pulled out to spot such leaks.

8. Examine your driving style. One of the oil companies has found that in its own fleet the difference between the worst driver and the best in terms of fuel consumption on similar models is something like 15 per cent. The following habits all waste fuel; frequent full-throttle acceleration; keeping the choke operative after the engine no longer needs it; frequent braking in traffic because of bad planning; cruising at high speed.

9. The engine may be running too cold because the thermostat has
the wrong heat value or has been
removed. This will also increase engine wear.