It would be great if you guys could write if you are using 0w30,5w30 or 10w30 oils, and write what car is it,and how much mileage and oil consumption is. (Since my mechanic told me that 10w30 dino oil is too thin for lubricate my firebird engine,and that it will be destroyed,I became afraid),So if you guys could show me that there is other people who use 30 weights dino,blend or fully synthetic oils,And have no problems with it, and it isnt destroyed your engine because of a use of a 30 weight oils,I can continue use 10w30 with better peace of mind. Thanks. I can start first; my car is pontiac firebird 92 v6 3.1 112500 miles on it,and oil consumption is about half quart/2500 miles.oil is 10w30 gm goodwrench.