is a lead replacement with Octane booster used in unleaded petrol for vehicles with unhardened vale seats.
Valvemaster+ is one of the few lead replacements which is tested by the FBHVC and reached the 3rd place overall.

FBHVC = Federation of British Historic Vehicle clubs
( http://fbhvc.co.uk)

Fuel-information: https://fbhvc.co.uk/fuels (Testprocedure is described in chapter: 'Additives')
Further information see: https://classicvalvemaster.co.uk

Proportioning, dosage:

One millilitre is enough for one litre of petrol. This bottle 250ml (1/4 litre) is able to treat 250 litres of petrol. This would last for nice holidays.

IMPORTANT:

Please follow the instructions written on the bottle. Not usable for Diesel engines.

VALVEMASTER PLUS

Lead replacement with Octane-Booster protects the cylinderhead of hammering from the valves.
This lead replacement has also the mission to lubricate the valve guides. This originally was the task of the lead in the petrol. Additionally the lead replacement has the task to lower the burning temperature. This in turn reduced the forces to the cooling system of Your car.
Just to remember: The burning temperature of unleaded petrol is higher than the burning temperature of leaded petrol.
Beside all this Valvemaster+ helps to keep the petrol system clean and helps to protect against corosion.
Additionally Valvemaster+ includes an Octane-Booster. A lot of our cherished old cars were built in the 70ies where higher octane values were common. I just think of the famous 'Four Star' in the UK which was app.Octane 100. (nearly racing petrol). Nowadays the petrols are situated in the area of 91..95. The ROZ91-ptreol is now not available anymore here in Austria, and I have seen petrol stations who offered petrol with ROZ71 in Russia.
Such low ROZ would result in heavy pinking under load conditions. Pinking can be reduced by changing the ignition timing. Valvemaster+ helps to reduce pinking but is no cure instead of changing the ignition timing.
Usually the increase is approximately in the area of '2'. This means if you use ROZ95 then you can reach approx. ROZ97. So, this is tnot the 'Four Star' but much cheaper for the similar benefit.
These values are not guaranteed, and are more a suggetion to give an idea of the expected values.

Safety datasheet: Safety Data sheet (SDS)