Originally Posted By: ammolab
Originally Posted By: john_pifer
Originally Posted By: Camprunner
Why don't car manufacturers recommend 10w30 today especially with all the turbo models sold now I would think it would hold up better under hard use?
The only reason is the marginal increase in economy with a 5W, and marketing by the oil companies.
You're correct; 10W will hold up better in an engine that's hard on oil, such as my 2016 WRX (turbo, GDI, boxer, high power density). Which is why I run PPPP 10W-30 year-round, when it calls for a 5W.
10Ws will also have much lower NOACK. PPPP is the best you'll find outside of an expensive boutique oil, at 4.7%. Matter of fact, I actually don't know of a boutique oil with better NOACK values. Maybe some kind of straight-grade might beat it.
Lively NOACK discussion going on
Here currently.
PPPP? What oil does the FOUR Ps represent?
PENNZOIL PLATINUM PURE PLUS