They have virtually identical approvals (SN, GF-5, Honda HTO-06, ACEA A1/B1 & A5/B5, dexos1). The M1 EP has a slightly higher flash point and the PP has a slightly lower pour point, but all their FP and PP temps are excellent. The viscosity index is virtually identical between them (169 & 170).
The M1 EP line is specifically marketed as a 15,000 mile long life oil, if that is an important consideration for your application. That's not to say the PP couldn't also do an extended drain - we see good results from both in UOA data frequently.
Sorry if this isn't much help. They are both very similar, excellent products. Pick the brand you like best, or the one that's on sale.
They have virtually identical approvals (SN, GF-5, Honda HTO-06, ACEA A1/B1 & A5/B5, dexos1).
M1 EP 5w-30 only claims ACEA A1/B1.
PP 5w-30 claims it exceeds both ACEA A1/B1 and A5/B5.
Technically, A5/B5 is a more stringent spec. Whether it matters in real life in OP's application, I have no idea.
R80RS thanks for the info. I got both pp and xom one ep in my stash but I was thinking of returning the xom ep because i consumed some oil the last time i used mobil 1 regular . Ps it was the first time using mobil 1. Ive used every other top of the line syn and never used a drop of oil. Also the 10 bucks rebate for pp makes it a lil better for my bank account. The only reason i got the m1ep was because it was the same price as the pp and i figured why not try it.