As long as the oil pressure resounds quickly with RPM I would not worry about it. I would run Mobile1 15w-50. It's a much better oil than VR-1 IMO!...........
Please elaborate if you can why Mobil 1 is "much better" than VR-1?
In many years on the board I have never received a factual answer.
I have a list of reasons NOT to run Mobil 1.
No. 1 A full synthetic oil is cohesive, not adhesive like normal oil. After the engine sits for a couple days, synthetic will drain down off the cylinder wall and bearings. Regular oil with stay in place indefinitely.
After dis-assembling 1000's of engines it is simple to tell the difference, synthetic is in the pan, but all the internal surfaces are coated if regular oil.
No. 2 The flash point of synthetic oil is ~550 deg. F, regular oil about 500 degrees, no significant value there?
No. 3 Generally the same weight/viscosity the synthetic oil will have a tendency to leak more than regular oil, and will almost always have less oil pressure, and drains like water when changed.
No. 4 The cam and lifters need all the help they can get in a performance build no matter if it is a flat tappet or roller lifters. The added spring pressure and RPM loads on the small needle roller bearings is tremendous in many cases, and unless there is an EP oil or additive, they can and will give up.
No. 5 The price of synthetic oil is more and "they", the ad guys, say it will last longer? In a turbo application oil gets contaminated long before the additives give up in either oil. Oil in a GN is usually done about 2000 miles, and even sooner depending on how much and often in boost.