Hello all, I just had installed a remanufactored LT1 into my Z. The mechanic told me to break it in for 500 miles , then change the oil. I'm a big Mobil 1 fan/Kool Aid drinker , so I asked if it was Ok to use it after this period was over. He told me to use regular oil for another 5,000 then synthetic. His reasoning is with synthetic, I might spin a bearing. My question, is this proper procedure? or can I use Mobil 1 after my first 500 miles ? thanks for reading and replying.

 

from general experiance, most people say to run dino oil(non synth) for about what you say, to aid in breaking in the rings, synth is too slick, and may never let the rings break in

 

My PERSONAL method is:

0-50: Dino, change;
50-500: Dino, change;
500-1500: Dino, change;
1500-3000: Dino, change;
3000-6000: Dino, change;
6000+: Switch to synthetic oil and filter regimen.

That's just me.

BTW, VW sells a break-in oil that comes in their new engines and is designed to stay in for 7500 miles. I cannot recall much about it or if it is synthetic or dino, but it might be worth a call to the dealership to ask, since it's specifically designed for that. If you want to go that way.

 

I've used synthetic in break-ins before and have had no problems.
Vette's and many other cars are first started at the assembly line with synthetic (mobile 1 in this case). You won't spin a bearing and the rings will seat fine.