[catback23]

your car is dieseling because it's running hotter, you shouldn't get a thermostat that opens at a different temp than OEM specs but if you do you should know what your doing and I wouldn't see much reason why you want the car to run hotter in the summer...winter maybe to get more heat faster but not much reason in summer...you can run higher octane gas which will probably help a bit but 230 is a hot engine and that hot is bad. Heat leads to shorter engine life, and more problems sooner.