I've used both Pennzoil Mercon V and Pennzoil Multi Vehicle ATF DexIII/MerconV in my car. I've been very pleased with both. I do not know for certain if they are indeed one in the same product, but i suspect they may be.
FWIW, i've only ever seen Pennzoil MerconV (In the yellow bottle) at PepBoys. Every other retailer location i've seen has the Pennzoil Multi Vehicle ATF (silver bottle) which is DexronIII/MerconV.
My power steering pump seems to like pennzoil products much better than the competition.