Castrol Valvemaster is a lead replacement petrol additive, 250ml treats 250 litres. With a very easy to use measuring device to aid correct dosage when filling up with petrol.
Castrol also produce Castrol Valvemaster Plus which contains an octane boost.
Many vintage engines run quite happily with no petrol additive as the engines were designed and manufactured in a time when there was no lead in petrol as today, there is no lead in petrol. However modern fuels vary in their octane ratings. Adding a fuel additive/octane boost when filling up may aid smooth running.
