I just bought a "new" 1996 Cherokee to replace the one I totaled. It has 194,000 miles on it, but the owner was a salesman and they are all highway miles. He also showed me receipts for aproximately 5-6000 mile oil changes. I think it said synthetic oil on the receipt, but it was a little confusing to read and I was in a hurry to leave as I was standing in the snow in a T-shirt. Anyway...is there any way for me to tell if there is indeed synthetic oil in the crankcase? I will be changing the oil right away, and I would like to use synthetic, but with 194k that would be a bad idea if it hasn't had it for a while.