Thicker viscosity does cause more viscous drag in the rod and main bearings. The times that I've gone from 40 to 50 weight in various cars I've noticed it. Don't know that I've ever gone from a 30 to a 40 weight.
Low ambient temperatures should cause lower oil temps which would also make your oil thicker and drag more.
I don't have anything that tells me what the stock rod and main bearing clearances are supposed to be for the evo9. Do you have those numbers?

Less crankcase pressure? As in less blowby meaning better sealing rings?

 

Lol. In reality all the wholesale does is pay for normal shipping. It even back out to almost 9-9.xx a quart not a big savings and I hope the car feels better when I get it. I can tell with my oil and example is I accidently got mobile 1 red cap" half asleep after work" and did ny oil change and when I drive to work it was like I had water inside the engine. I looked it was high milage a thinner mobile 1 then put VR1 semi synthetic 10w30 and it ran like a champ much better idle anit did not feel like water. So amsoil has 2 oil changes to make me want to keep it. If not going back to VR1 Racing Oil. I will be doing a engine flush before useing amsoil at my tune shop so there will be no mixing of oil for mixed results.

 

Well like I said I will try it before I honestly knock it. I DD my car so I normaly allow it warm up and thus I don't think I should experience much drag when he oil is hot.

 

How do they get all the flush fluid out before you put the new oil in?

 

The machine gets it all out its super hot IIRC so it wont be in there when we get done also its not like water it a chemical that I think evaperates and its the same thing they use when they do services at the dealership.

 

There are zinc oil additives that will eliminate the low zinc level problems. Most of these are targeted at the classic car market, older cars needed the zinc as a lubricant. One I came across is Zddplus. for a high dollar engine, it seems like cheap insurance.

 

That's a bit like using octane boosters when higher octane fuel is readily available. The best prospect is just to use an appropriate oil, which is usually readily available from better auto parts stores.

 

Quoted from the Amsoil site where it says adding oil additives is not recommended (at least in their oil. I quoted 10w40 but it says it for their other oils as well, ATM, ASL, etc:

MIXING AMSOIL
AMSOIL Synthetic 10W-40 Premium Protection Motor Oil is compatible with conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils, however, will shorten the oil life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed. Aftermarket oil additives are not recommended for use with AMSOIL Synthetic Oils.

 

Is Dominator 10W-30 Racing Oil RD30 1575 1424 a good oil for a FP BLACK?

 

we run it on a race evo with stock turbo, so its even better for the FP turbos that use the similar metals bearings and shafts, it will minimize metal to metal contat in all cases

 

Its on the appoved oil list from FP also Robert suggested if I want to use Amsoil that I use dominator since its got allot more zink and phosphorus content. I use it and no problems.

 

amsoil 10w-30 works awesome with my MR for the past 4 years now

 

Do you have a red or black? If not then 10w30 is irrelevant there are certain oils for the FP Red and Black that can be used read the thread before posting.

 

I wonder if Eneos 0-50w is suitable for a FP RED or FP Black??

 

I doubt it. Just run what's approved l like the 10w30 Amsoil Dominator