Classic Valvemaster – the fuel additive that saves kit classic cars from ethanol-rich petrol especially with the advent of E10 petrol in the UK from September 1.

When it comes to liquid engineering, internal combustion engines rely on quality oil and quality fuel to run efficiently. Over the years, however, tightening emissions regulations have forced changes within the petrol industry and altered the formula of standard fuel.

Leaded petrol disappeared from UK forecourts at the turn of the millennium, E5 biofuel was standardised in 2019, and in September 2021 the recipe of standard grade unleaded petrol is changing to double the content of renewable, non-fossil ethanol. This new petrol will be identified by the code E10.

While these changes are welcomed in order to help cut harmful emissions, they have always impacted the use and performance of historic vehicles on the roads. Just as Valvemaster was the go-to fuel additive that allowed owners of classic vehicles to switch seamlessly from leaded to unleaded petrol, Classic Valvemaster is once again being relied upon to neutralise the corrosive effect of ethanol in classic car fuel systems.

Classic Valvemaster lead replacement additive

  • Unique phosphorus formula protects against valve seat recession
  • Ethanol stabiliser protects existing fuel systems and enables the use of E5 and E10 biofuels in classic cars, motorcycles and pre-1996 petrol vehicles
  • £12.95 for a 250ml bottle

Classic Valvemaster Plus lead replacement petrol additive

  • As above but contains an additional Optimise-Plus friction modifier to increase acceleration by up to 3 per cent and improve economy by up to 2 per cent.
  • £14.95 for 250ml bottle or £12.46 each and free delivery when ordering six or more

Classic Valvemaster and Classic Valvemaster Plus offer optimal protection against the valve seat recession that is associated with the use of unleaded fuel in engines designed to consume fuel with lead added as an anti-knock agent. Similarly, both Valvemaster products contain Etha-Guard stabiliser to help protect against rubber and alloy corrosion in all 95+ octane petrol with up to 10 per cent ethanol content.

Each 250ml bottle of Valvemaster is designed to treat 250-litres of fuel, which makes it the most cost-effective way of maintaining the internal health and well-being of your classic vehicle.

More information on each product can be found by visiting, while purchases can be made through the Castrol Classic Shop on

Check to see if your vehicle is affected by the switch to E10 petrol by visiting ENDS.