Should you not wish to have your car classic car engine converted to consume lead-free petrol by means of cylinder head conversion etc, then you are highly advised to use a petrol additive. The lead in petrol plays two major roles; firstly it prevents valve recession into the head by means of lubricating action, and secondly provides an octane boost to ensure correct burning and alleviate pre-ignition (reducing pinking). Either of Castrol's products are designed to replacement the lead element missing in unleaded petrol. The Valvemaster Plus also contains an octane booster to boost the octane level of unleaded petrol up to the desired 98 level (equivilent of the old 4 star) for correct running of classic cars. Should you not wish to use the octane booster then we would advise you to either alter the engine timing to account for the lower octane rating of unleaded petrol.
With obvious concerns about the efficacy of Lead Replacement Petrol (LRP), especially as regards its lack of a British Standard, and the petrol companies' own warnings regarding the unsuitability of their product for "everyday" use, most owners are opting to use Castrol's Valvemaster plus.
In a test performed by the Federation Of British Historic Vehicle Clubs Castrol Valvemaster was shown to offer the highest level of protection. Valve master is recommended by many motoring clubs.
Scan 1st page of Castrol Valvemaster
Scan 2nd page of Castrol Valvemaster
Also supplied is a measuring device in order to make it easy to calculate how much additive to use - 10 ml of castrol Valvemaster treats 10 litres of unleaded fuel.