Roush 427R oil question?

[twobjshelbys]

Here's the info I got back from Roush this week.

My engine was back there. It has a little over 4000 miles so they refreshed it with Mobile1 10w30.

One of their engine guys piped in with the following advice (summarized from his email)

a. There is no downside to staying with the regular old petroleum 10w30
b. For synthetic, 10w30 is still the first choice.
c. If you live in an area with high ambient temperatures or your driving style is "spirited", then he suggested a 15w50 synthetic.

Then he cautioned: always keep the oil temp below 230*F and he mentioned "engine damage that would not be covered by warranty".

My specific comments on his guidelines:

During this part of the season I definitely have the higher ambient temperature issues - it's in the 90's today and for the rest of July/Aug it will be.

My oil cooler keeps oil temp (in steady state driving) at the exact same temp as water, all the time, and both rarely move above 80*C. In fact, it takes a while for oil to climb to water.

Given this, I'm inclined to stay with the 10w30 synthetic for the forseeable future.