I traded a 1991 mr2 gen4 and bought a new OEM radiator cap and to make a long story short, this little guy (OEM radiator cap) cost me $2500 in time and money. I rebuilt the head, replaced all coolant lines, radiator, fan, timing and water pump etc and the car was still overheating. I bought this and the car stopped heating. I think the extra pounds of pressure were required or the "new OEM radiator cap" was faulty. Anyway, this purchase was amazing. I only wish I had found it sooner.