my lo3 tbi has 144,000. it has no oil leaks, dosent smoke runs really good. if i go synthectic what kind and what weight? I run 10W30 now with conventionals. I figure in louisiana's type weather that should be ok.

 

Mobil 1 syn and Amsoil are the best. I use Mobil 1 10W-30.

 

Don't change to syn. at this point in time. You are at the end of your seal life, and if you have no leaks do not mess with success. Synthetic will flush away wax deposits that tend to seal the engine and keep the oil inside. At that mileage it is a testament to the fact that ANY quality oil will give your engine long life. Just keep doing what has been done, who the hell knows-maybe it will see 300K.

 

I forget who said it, but synthetic won't create leaks, but it will make the ones there worse.