My first visit and post to this site and I can't tell you how great it is!

I want to go from a 195 to a 180 degree thermostat on my '92 Bonneville SE (only 54,000 miles) as summers here in NJ can be a real bitch - especially when stuck in traffic on the Parkway going down the shore on weekends.

I recall a GM mechanic recently telling me that switching to a cooler thermostat might negatively effect the computerized components, upset the emissions, fuel economy, cause possible carbon build up on certain parts, and distract from the normal operating temperature the engine was specifically designed to operate at. Has anyone else heard these type of answers before and would switching do any real harm to my car or would it actually be more beneficial to go to a cooler operating thermostat?

Welcome to the forum.. I'll save Will the hassle and bug you to please update your sig to include your car'* year trim and any mods as it makes it easier to help answer any question in the long run

check out the techinfo in this site.. this has been discussed before, and I'll have to say no it will not affect your car in those cases that you're mechanic has stated. Most mechanic would always recommend using OEM, and running 180 T-stat has it'* benefit of keepin your engine cooler and thus prolongin the life of the head gaskets. A lot of the members here have run the 180 T-stat ( includin me ) and none have nothing but good to say. Now running a 160 T-stat maybe too low since some members have attempted that and had negative result throwing CES lights. I remember someone posted once about the ACTUAL optimum range for these engine.. and 180 is fine.. I belive it'* 160 - 200F.. could be wrong.. someone can fill you in on that

Again.. welcome to the forum.. you'll love your stay here