The effect of oil on cold start is that the synth presumably has more consistent viscosity over a range of operating conditions-- at cold start the higher visc of dino oil could require more load (more idle air bypass) to reach the target idle speed. This would increase cold start emissions for the dino oil equipped car. Just thinking aloud...

Also, oil temps take MUCH longer to stabilise than coolant temps. Just stick an oil temp gauge in your oilpan and compare it to a real water temp gauge. You'll find it takes oil far longer to reach operational temp than water, even on cars with piston oil squirters.

 

The car to car variance has more to do with the GAS used than the oil used. That said - having taken down 4 evo motors to the bare bolts which were all borken in on syn oil and now one evo motor - mine which was broekn in on dino oil - it is obvious that evo bearings do not break in well on the synthetic oil

I would recomend using non synthetic oil all the time and just changing it very frequently

 

So I have 8k on my motor now, all on Mobil 1. Could I put in Dino and run the snot out of it for a few 100 miles just to get the bearings to break in properly AL? Then switch back. Any benifit?

 

no sorry maybe next time around

 

I don't see how it could hurt. why not give it 3k on dyno. I would do a flush about 1k on dyno and then change again with dyno and do 3k. Back to mobil 1 or what every your going to be using.

It can't hurt. It will not harm your car. If it helps great if it does not oh well worth a try?

Eric

 

I agree no harm in trying And Id actually think that the rings will have a decent chance at sealing better but the bearings are a totally differnt thing if they have any wear then this wont help them at all.

 

Well about the bearings it might help alot.

 

How would break in with dino oil be better? I always thought that synthetic is better. That dino oil leave deposits. Isn't the purpose of oil to reduce friction and that leaving deposits increases friction? If it's the deposits that help, then I would assume that using dino oil anytime would help.

Could it be that synthetic only EVO's just need more miles to fully break in the bearings?

I am totally confused and pissed because my oil smells like a gas tank and I have 9k miles.

Al - how many miles were on the synthetic only EVO engines that you broke down?

 

There is certainly no harm in running non-sythetic for a few thousand miles even if the engine has been broken in on sythetic. I suspect things would have worked out better if it had been broken-in on non-sythetic from the start, of course. As for running dyno oil even after break-in, I would not recommend this. In a high boosted and high specific output engine such as the EVOs 4g63, a good synthetic will be more resistant to break-down when subjected to the unusually high cylinder temps seen during operation. A good sythetic will also prolong the live of the turbo by being much more resistant to bearing coking. It's certainly a tradeoff which is why one oil is better for initial break-in and the other oil is better for long-term performance and reliability.

My 2c,
Shiv

 

So what kinda of dyno oil do u recommend Shiv? And how should I break-in my car? Hard (reving to 5-7k) or gentle (3-4k)? I trust your expertise and many years of tuning high performance cars.

Jack Boyer

 

As mentioned before Dino oil is not as slick as synth...when an engine is new the rings need to lapped to the shape of the bore (not always perfectly round) the slightly abrasive quality of mineral oil will make sure all components are matched to thier corresponding counterparts perfectly...in the case of piston rings the main sealing or lapping in will take place in the first 50 miles...also varied throttle openings are also preferable during this time....
If synth is used for the break in, because it is so slick, no lapping takes place.....and once you have driven a few thousand like this it is NOT possible to reverse the process....my 2c

 

I know you asked for Shiv's input but If I could say that a hard to 5K break in is most certainly the way to fly...plenty of overrun revs ( to lap cylinders, but not induce harmful cylinder pressures) but keep loading/laboring on engine to a minimum.....the worst thing you can do is pick up your shiny evo from the dealer and then sit on the interstate at 3k for a hundred miles with synth in the pan...my 2c
Oh ....and it's "Dino" as in Dinosaur...not "dyno" as in the test equip...lol

 

thanks for the response limey. Is there anything that we can do if we broke the car in with synthetic to help seal the rings better? sounds like we're going to have to live with it.

 

Well I'm going to be the Guinea Pig of sorts. I have 8400 miles all on my evo running M1. I have been using approximately 3/4 quart of oil between 3000k oil changes. I just drained teh M1 and put in some Turbo approved dino. The M1 I took out did have a bit of a gas smell to it. I'll run that dino for the next 1100 miles until my next scheduled oil change. See what happens. I'll be sure and let it cool a bit longer before shutdown to prevent coking.

Any thoughts positive, negative. Is there still a chance it will help everything seat tighter? As Al suggested maybe it will help the bearings break in better?

 

Agreed - the problem is the bearings never had a chance to seat in easily in the begining and now prob have strange wear marks