I needed to add some oil after burning off a little from my last track day. I usually buy whatever synthetic 5w30 brand is on sale for around $5/quart at Pepboys or Autozone but haven't seen any on sale lately. I was in Walmart the other day and since people have said Walmart brand is as good as other brands, picked up a 5 quart jug of 5w30 synthetic for $18. They were out of 1 quart sizes and even the 5 quart jugs, but I happened to find a 5 quart jug on the ground hidden behind some other 5 quart jug. They had a sign apologizing for their lack of supply of Mobil 1 because of the Gulf Coast hurricanes (Christ it's been like 6 months and gas is cheaper now than it's been in 3 years! - how can there still be a supply problem???). The jug looked clean, but I couldn't find any sell-by date on it.
It still had the seal on it when I opened it, but shortly after pouring some into my engine, noticed a distinctive skanky smell. It looked clear like any other new synthetic oil. I don't know how to describe the smell - maybe somewhat fishy, or maybe something I've smelled in a machine shop. I've never had new or used motor oil smell like this before, and I haven't opened a new quart of non-synthetic oil in 5 years and used everything from Mobil 1 to Castrol Syntec to Penzoil Platinum. So does Walmart 5w30 just normally have this bad smell? Also I wished they'd design a 5 quart jug that you could pour from without spilling like 1/2 quart from the top without a funnel!