Originally Posted By: addyguy
This engine has twin turbos, so neither produces a HUGE amount of boost, so there isn't that much strain on the reciprocating parts - the turbos are power 'supporters' not the main way the engine makes power. Just a guess. It probably will also have a sump capacity of over 6 quarts, so more oil to take the stress.
But, I agree with others, I'd use syn. in it for extra peace of mind....
That's not the way it works. Each turbo produces the same amount of boost, whatever the boost guage reads, boost isn't split in half. Turbos tend to increase low and midrange torque a lot which will put more of a strain on everything, especially rod bearings.
I think the problem is twofold. One is the high heat that will be developed. That 20wt will easily be a 10wt after some hard running. The other is the low HT/HS associated with the 20wts in a high specific output engine. If I were buying that car it would have at a minimum a quality 10w-30 or thicker.