TetraBOOST E-Guard 15 is not just another fuel additive with lead replacement, it is the only additive which contains Tetraethyl lead which converts unleaded fuel into true 4 star or 5 star leaded fuel for use in classic and vintage cars. It also includes Ethanol protection which prevents damage to rubber fuel components in older vehicles caused by Ethanol present in modern unleaded fuels.Converts unleaded fuel into real 4 or 5 star leaded fuelPrevents pre ignition and valve seat recession in classic and vintage enginesBoosts octane up to 106 RONSlows fuel burn rate for improved combustion which provides better throttle response and engine pick upPrevent Ethanol damage to fuel system componentsSuitable for road or Motorsport useTetraBOOST E-Guard 15 is a solution containing tetraethyl lead in aromatic hydrocarbons combined with chemical scrubbers which when added to unleaded pump fuel converts it to a true leaded fuel suitable for older engines with soft valve seats which require the a