High quality retro-JDM style radiator caps by Japanese manufacturer Maruha.
Available in 3 Pressure ratings:
0.9 Bar for daily use
1.1 Bar for track use and prolonged spirited driving
1.3 Bar for heavy track use and prolonged hard driving
These caps feature a silicone sealing ring which provides a longer lasting seal compared to the OEM cap made with natural rubber.
A higher pressure radiator cap will increase the pressure in the coolant system before allowing coolant to expand into the expansion tank. By keeping the coolant at a higher pressure - the boiling point is raised, therefore increasing cooling efficiency.
Mk1, Mk2 & 2.5 models of MX5 / Miata
MK3 MX5 / Miata
Warning: The old rubber hoses on the engine may be crusty and perished and may be more prone to failure from a higher pressure cooling system.