I've been using Schaeffer products for just over 3 years and I do have one regret - I wish I'd have known sooner about Schaeffer Oil Company. I have used their motor oil, differential fluid & transmission fluid in our two cars and my truck without issue, failures or malfunctions. I also use their 'Neutra' product periodically with good effect. The oil and Neutra did increase my car mileage way more than I ever expected and performance was solid. This is good stuff and over time, will save you money as long as you trust the product. I was one of those old school guys who liked to go with the 3 months, 3000 mile "change your oil & filter rule" my Dad used to beat into me. Not anymore - the Supreme 9000 full synthetic motor oil is all I use in every vehicle (with high end filters, of course). It is second to none. Schaeffer's has been around since 1839 and it has stayed a family owned business ever since. It is a U.S. company based in St. Louis and they have a bulletproof warranty. Vendor on Amazon for this specific transaction was flat-out amazing - I needed a case in a hurry but it was late in the day. The goods were on my doorstep 20 hours later. Impressive (I do have Prime, but gladly paid the $11 for overnight - bargain). Thanks for the great product, the awesome service and Amazon. Smiles all around.