Im finally finishing up my Evo 8.5 project. Basically im dropping a brand new Evo IX crate motor into my Evo VIII.

But anyway, these engines come directly from Mitsubishi and have never been turned over. Im trying to decide the best oil to use for the break in period. Ive seen a few older threads indicating that it is good to use a conventional oil for the first 1500 miles and then switching to Mobil 1.

Does anyone have an opinion or any experiance in doing this?

 

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I would just use 10w-30 conventional oil for first 1500 miles. I used vavoline but anything else is fine.

I did oil changes at 20 miles, 250 miles, 500 miles, and 1500 miles.

 

And once I hit 1500 I can switch over to Mobil 1?

Ive heard that this helps reduce blow by / fuel in your oil...

 

That's what I do. Then after those changes I switch to synthetic.

 

Then that's what I will do. Thanks guys! If anyone has any opinions let's hear em...

 

What about conventional oil affect on the turbo?

 

What about it? People have been running conventional oil in turbo vehicles for a long time now. It doesn't do anything to the turbo.

 

Actually, the high temps inside the turbo tend to accelerate breakdown of conventional oils, due to their inferior thermal stability. One effect of this was coking, which was a common problem back in the old days (and why turbo timers were invented). I'm not saying this is necessarily a factor during the break in period, but it's why synthetic oils are especially advantageous in turbo engines.

 

Have you sure that the engine has never been turned over? I was under the impression that all factory built engines nowadays are run in on a stand. I have heard that even large aftermarket builders do this because of the cost of returns.

 

Turnkey crate engines that just need to be dropped in are oftentimes run in at the factory. Shortblocks, longblocks and such typically are not.

 

why would you want to risk ruining the break in? Just use full synthetic and be worry free, i would use it. I would not want to take the chance of something going wrong on my new engine.

 

Again, from what I understand conventional oil helps condition the rings and bearings. It has been noted that even when Evo 8 and 9s that came from the factory carrying Mobil 1 had problems with blow by. Anybody want to add to this fact?

 

It could be added that quite a few high performance OE engines on the road today are run in on synthetic, including AFAIK, all the exotics. I find it hard to believe they all suffer blowby issues. I never had any.

 

Understandable. And you would think that the engineers at Mitsubishi wouldnt specify Mobil 1 and add it as the first oil off the assembly line if it was a problem. But many have suggested on this forum and others, that running conventional oil during the break in period is better for the motor and obviously cheaper.

This is a very interesting subject. Im also interested in knowing if this is just a 4G63 thing...