Folks - a few reasons I think Amsoil lubricants are better.
We all know it's difficult to do a generic comparison. Maybe ideally - pick a car and engine (a sample of 20-30 of that car for each oil), a given location, driving route, driver control, etc - then each oil company pick their best oil for that application. Do UOA's with ferrography, particle counts, tear downs, radioisotope tracking, etc. I doubt that would even come up with a winner.
I'm not trying to start a war, these just my thoughts.
1) Amsoil does not compromise on additives to save a few pennies. As with all companies, cost is a concern, but not a driver. I freely admit Amsoil had their weakest moments in the early 2000's and found themselves quite equal with M1 and in some cases lagging. I think this was due to some weakness in the R&D lab and some formulas where they relied on their suppliers too much, but they listened and learned and came out much better in the long run. Amsoil buys high quality base oils and additives, Mobil does too.
2) Amsoil has lead the USA consumer market for extended drains, without flinching. We quibble about a few PPM's of metals in a UOA's, but Amsoil keeps performing. UOA's indeed do NOT show everything, but what other oils post with some regularity in the 15K+ OCI range? Who else publishes a clear OCI guideline for their various products? Mobil seems to jump all over the map.
Amsoil OCI guideline:
http://www.amsoil.com/lit/g1490.pdf
3) Amsoil has a more rounded lubrication line available to the general public. Do the other synthetic manufacturers offer a synthetic SAE 30 HDEO and an synthetic SM additive level 0W-30 and a synthetic 5W-30 HDEO and a synthetic 20W-50? Motorcycle oils, boat and PWC oils, small engine oils, scooter oils, four 2-cycle engine oils…..all easily available. I didn't mention the gear oils, tranny fluids, greases, fuel additives, etc. And excellent filtration products. Are all these products the BEST in in each class? No they aren't, but some are, and all are near the top. Do I wish they had even more products? Of course!
Amsoil Timeline:
http://www.amsoil.com/timeline.aspx?zo=515729
4) If you run the correctly specified modern oil of any base oil, group II and above, for under 3K miles, in the average USA NA car, it doesn't really matter for wear in the long run. Drop the temp below 0°F, have a turbo, go to 5K-10K-15K+ oci's, drive hard in 100°F+ weather - I would recommend a good synthetic oil. M1 and Amsoil will do fine, Amsoil will do better in the hot because frankly it won't shear (as the 0W-40 and some of 5W-30 formulas do) and Amsoil doesn't seem to show the anecdotally observed Fe spike in certain engines. I know I'll get heat for this, but it's there! Is this Iron spike a super bad thing? No it probably isn't. Will it effect longevity of the engine? Probably not. Maybe it's indicative of how well M1's deposit prevention additives work. Is the shearing always a bad thing? No absolutely not. I have a tendency to thing the M1 0W-40 is designed to shear to SAE 30 range. On the same token, when the old formula Amsoil motor oils (really only the HDD 5W-30 now) moves into the SAE 40 range, people should not get alarmed either - because frankly it still protects very well.
5) If you buy $75-$100 worth of Amsoil lubricants in a year period, becoming a preferred customer makes the prices nearly the same and in some cases lower than M1. When I see standard M1 5W-30 in my local store for $7.99 a quart, it's really a no brainer because stacked up against Amsoil ASL 5W-30, I'm sorry but $5.80-$7.80 a quart, Amsoil is a better value. Now gallons are $22.75-$28, so yes M1 is a little lower purchase price in bulk from Wal-Mart.
This no means a hit on M1 products. These are my biased observations - I readily admit I have a bias - this no huge secret with the icon by my name every time I post. But honestly even if I was not an Amsoil dealer, I highly doubt I would use Mobil products. Why do you think I got into Amsoil in the first place? I wanted something better than M1.
Everyone is totally free to think M1 is better than Amsoil, or that they are equal.
Thanks,
Paul