Hi all. Just replaced the radiator, water pump, thermostat, all hoses and radiator cap. The new cap is 13 psi. The old cap (no idea if it was original) was 16 psi. My uncle's 93 renegade's cap is 16 psi. Haynes manual states all 6 cylinder engines use 16 psi. Can you tell me which cap should be used? Thanks.