Exceptional product. Lasts 10 years. Engines run cooler, great if car in storage or low use, preserves cast-iron/aluminium/brass, boiling point 180degC and frost protection down to -42degC, exceptional heat transfer via low viscosity, anti-foaming, balanced pH preventing lime scaling, preserves rubber hoses. Use undiluted. Unique Red colour that turns Yellow if head gasket fails - but reverts back to red again once fixed - so its reusable.