How often should I change the oil in a classic car I hardly use?

At least once a year is common specialist advice for a lightly used car, because oil degrades with time and short runs as well as with mileage. Follow the car's handbook or your specialist where they say otherwise.

Can I use E10 petrol in a classic car?

The Government advises owners of classic and older vehicles to use E5 petrol, which is still sold as the 97-octane super grade at many larger filling stations. If you put E10 in by mistake, a single tank should do no harm; fill up with E5 next time.

How do I tell how old my tyres are?

Look for the four-digit code at the end of the DOT marking on the sidewall. The first two digits are the week and the last two the year of manufacture, so 2318 means week 23 of 2018.

The Classic Car Owner's Guide

Owning and maintaining a classic car

By Jon Cosson · Last checked 13 October 2026

A classic car rewards regular, unglamorous care far more than occasional big spending. Most classics cover few miles a year, so time does as much damage as distance: fluids age, rubber hardens, batteries go flat and damp gets in. This section covers the general care every classic needs, whatever the make.

The essentials

Service by time as well as miles. A car that covers a few hundred miles a year still needs its oil, filters and fluids changed. Many specialists recommend an oil change at least once a year on a lightly used car, whatever the mileage.
Change the brake fluid. Most brake fluids absorb water from the air over time, which lowers their boiling point and corrodes brake parts from the inside. Follow the interval in the car's manual or the fluid maker's guidance; many recommend every two years.
Look at the tyre's age, not just its tread. Rubber hardens and cracks with age even on a car that rarely moves. The four-digit code on the sidewall gives the week and year the tyre was made.
Use the right petrol. Standard 95-octane petrol became E10 in Great Britain in September 2021, and in Northern Ireland in November 2022. The Government advises owners of classic and older vehicles to keep using E5, which remains on sale as the 97-octane "super" grade at many larger filling stations.
Keep the battery charged. A flat lead-acid battery left standing is quickly damaged. A battery conditioner (a smart charger designed to be left connected) or disconnecting the battery keeps it healthy between drives.
Keep water out. Clear drain holes, wash off road salt and dry the car before putting it away. Rust prevention is mostly about stopping water sitting where it cannot escape.
Join the owners' club. For almost every classic there is a club whose members know its weak points, its parts suppliers and its specialists.

Pages in this section

Coming to this section

Servicing a classic yourself; finding a specialist; batteries; electrics; fuel and ethanol; engine oil; gearbox and axle oils; cooling systems; brakes and brake fluid; tyres; ignition; carburettors; rust prevention; bodywork and paint; interiors and hoods; upgrades and modifications; planning a restoration; driving a classic today; winter driving; fault-finding; clubs and events.

FAQs

How often should I change the oil in a classic car I hardly use?: At least once a year is common specialist advice for a lightly used car, because oil degrades with time and short runs as well as with mileage. Follow the car's handbook or your specialist where they say otherwise.
Can I use E10 petrol in a classic car?: The Government advises owners of classic and older vehicles to use E5 petrol, which is still sold as the 97-octane super grade at many larger filling stations. If you put E10 in by mistake, a single tank should do no harm; fill up with E5 next time.
How do I tell how old my tyres are?: Look for the four-digit code at the end of the DOT marking on the sidewall. The first two digits are the week and the last two the year of manufacture, so 2318 means week 23 of 2018.

Checked 13 October 2026 against GOV.UK (E10 petrol guidance), the Federation of British Historic Vehicle Clubs, and brake fluid and tyre manufacturers' published guidance.

An independent guide from Thornton-le-Dale. Not connected with Mathewsons or the programme.