Hey guys I wanna run full synthetic oil in my truck, which I thought would be a damn good idea but I heard from some guy that your not supposed to run it unless your engine is good and broke in, which mine was just rebuilt and has 1,000 miles on it. He told me my rings wouldnt seat right if I put sythetic oil in it. Is he just blowing smoke up my a#! or is this true??

 

No he is right,no smoke blowing.You have to let the rings seat in the cylinder and seal themselves,It doesn't matter if it is diesel or a gas engine.I would give it 5,000 miles and it will be broke in or better yet ask the builder so he call tell you.

 

I am the builder hahha I've built a few of them I always run just regular Valvoline Premium Blue from the first start but those were other guys engines so I dont know what they did after I gave it back to them. I just told them to change their oil after 500 miles, but I'll just be safe then sorry and just keep running it with my normal oil till around 10,000 miles then I'll switch to synthetic, I just never heard of synthetic oil making your rings not seat proparly but oh well, learn something new everyday.

 

Go for a true Group IV Synthtic oil - AMSOIL, MOBILE 1, Royal Purple, Redline Racing

Rotella syn is a group III Syn afik.

I believe Cummins recommends 30k before switching to syn.

 

don't ask oil questions on this site haha it's very dangerous, just see the thread called Opinions on motor oil, haha it's funny, but my question about this is why do some engine manufactures use synthetic oil as factory fill? I'd run dino oil for at least the first 2 oil changes

 

Your rings will still seat, it may just delay it a little. I always recommend changing the first time at 1-2k, then running another 4-5k interval on dino, then switch to syn. I'm conservative that way. Gassers I go sooner. My harley goes at 1000 miles. My lawnmower at 8hrs...the list goes on