For petrol cars, change the oil at least every 10,000 miles or once a year. For diesel engines, every 8,000 miles or about every 9 months. Modern synthetic oils now used in diesels mean you no longer have to change oil twice a year.  While modern oil is generally incapable of actually wearing out, its job is to trap dirt, carbon and metal dust from your engine and 'suspend' it in the oil while still lubricating. The dirtier it gets, the harder its job becomes and the less effective it is. This results in heat build-up and more 'drag' or friction inside your engine which costs you in extra fuel. It can be expensive to change your oil. Our Espace uses 8 litres of synthetic oil every 18000 miles. We've cut that interval to 9,000 miles and at £55 a go for oil alone it's dear. BUT, we are preserving the life of the engine, and cutting fuel costs into the bargain as well as keeping up the final re-sale value of the car because of its excellent service history.

A dirty air filter will reduce the volume of air getting into your engine. These items are cheap, easy to swap, even by a complete novice,  and should be changed every 5,000 miles or so. You WILL notice better performance and better fuel economy with a clean air filter and you should change them in between service intervals. Better still, see if you can buy one of the K&N cloth type filters that can be cleaned and re-oiled. They improve airflow into your engine by as much as 27% and will pay for themselves in less than a year in fuel savings alone.

Tyres and brakes. ATS tell us that one in 8 cars they look at has binding brakes. Brakes get clogged up with brake dust , and road dirt and salt slowly stop them working properly. Once they begin to bind, or stay partly on, they are a killer waste of fuel. You should have your brakes checked at least once a year. New pads will cost less than £50 a set generally and can be fitted by Kwik-Fit, ATS and most tyre fitters. They can then check and clean your brakes to ensure they don't bind and waste even more precious fuel. You may not even notice brake bind, but it will hurt your pocket.

By law,  tyres need 1.6mm of tread depth across 80% of the tyre. In reality, they need at least 2mm to 3mm  across the whole tyre or they become inefficient in fuel terms. Keep them blown up. Check at least every 14 days as tyres lose air all the time. Once they get to 2mm or so, change them. It will save you fuel and make your car a lot safer to drive, especially in the rain.