Ask them if they used a 0w-40 or a 5w-40.......then ask them what brand they used.....if they claim it was a Pennzoil 0w-40.....then they are screwing you over.....the Pennzoil that meets the MB std & has replaced the Mobil-1 0w-40 is Pennzoil Ultra Euro 5w-40......it doesn't come in a 0w-40. If they put in a 0w-40 Pennzoil it may not even have been a synthetic.....let alone a synthetic that meets the MB std.

There is a new Pennzoil Ultra 0w-40 (I think it's for SRTs)......but it's the Pennzoil Ultra EURO 5w-40 that's on the MB 229.3 & 229.5 approved list.