What should my pressure be? Make Model Spec 155. 1.8I 16V TWIN SPARK155. 1.9 JTD155. 15 OPT155. 2.0I 16V TWIN SPARK155. 2.0I 16V TWIN SPARK SUPER155. 2.0I CLOVERLEAF. Q4155. 2.5I V6155. 2.5I V6 16 OPT