The way I read it initially was in accord with the way Paul has it stated; the "normal" is OEM typical reccommended and "severe" is 2x the OEM severe rec. Hence it could be lifetimie for normal or 2x for severe.
I'm going to go a bit off-topic, but come around at the end, so bear with me ...
(this rant has nothing to do with Amsoil, but the OEMs)
What is "normal" to an OEM anyway? Their ambiguous statements are hard to quantify; their exclusionary statements are meaningless often. To some large degree, I understand why; it gives them wiggle room in the warranty limitations.
But if we are to believe the mass BITOG membership mantra, which often reflects the OEM position, then 99% of the whole world's lubricant operations would be "severe" use. How can that be "normal" if the vast majority is "severe". Would not that infer that "severe" is "normal" and to be expected in every day life? It's simply improper to call something "normal" if you don't expect it to be the majority of the experience. It's diametric to define "normal" conditions as not typical or expected often.
After all, how dusty is "dusty conditions"? How much idling is "frequent idling"? etc ...
Take my fleet as one example. I live in a very rural area, and travel to the big city to work. I drive stop/go traffic and cruise speeds as my commute is about 50/50 mix (estimated). It get's very hot in the midwest (we all had a super dry, very hot summer last year). It gets very cold (will typically get a few snaps down near zero, but averages +18F in Jan). About the only thing I don't do with my Fusion is sit and idle; it's not a taxi. I am in "dusty" conditions every day as we live surrounded by farm fields and have a 1/2 mile long gravel driveway. The dust my vehicle ingests is probably far more than the average person; they don't live in farm areas and they don't have gravel driveways. The only way I could get my Fusion into more dust would be to race in the desert or use it to pull a plow 12 hours a day.
And then there's my wife's Village; total soccor-mom vehicle. That thing starts probably 20 times a day. It rarely drives more than 10 miles for any given trip, and yet she averages about 15k miles a year; that ought to tell you how much time she spends running short-hop errands. In the same small, dusty, hot and cold town. Many times her start/stop driving distance can be measured in blocks.
And then there's my truck; I absolutely hammered that thing as best I could two years ago, purposely leaving the oil level as low as safely possible, driving in mountains at WOT for minutes going uphill, driving through hours of heat in AZ and UT, all while pulling a travel trailer and using dino 10w-30 HDEO in the Dmax. If that wasn't "severe" by OEM definition, I don't know what was ...
And yet my UOAs come back fine. In fact, they come back stellar. The car, van and truck have never shown any indication that "severe" service as defined by the OEM results in any additional risk whatsoever. So how worthwhile is the word "severe" in a service manual anyway? If we all operate this way, then by default "severe" is normal! When your UOAs show that your personal results are right in line with everyone else, then one of two conclusions can be drawn:
1) everyone's use is severe, and therefore severe = normal by concept of exposure
2) severe use does not manifeset into wear differences as opposed to otherwise "normal" definition, and so severe = normal by concept of UOA results
The term "severe" in a manual is there to limit the liablity of the OEM, and it's done so at our cost (the OCI is upon us and not them).
In short, I understand that the OEMs are eager to define "severe" as just about anything but grandma-like highway crusing, because it protects them. But the facts of reality show that most of us are not affected by the "severe" parameters in our life. And, "severe" is "normal" from a point of expected exposure. Certainly this is predicated on a sound mechanical condition of your equipment; leaks and contamination are going to wreak havoc. But when you maintain your equipment well, there is no reason to believe that "severe" (as defined in a manual) equates to any real shift in risk in your everyday operation.
After all, think of the dichotomy of the what OEMs want us to believe. Every OEM that makes a truck, wants us to believe they make the toughtest, meanest, most reliable and robust, dirt chewin'est, mud slinging-est, wood-hauling, excavator-towing, bad-booty vehicle ever made on this plant. They make videos of how rough-and-tumble their trucks are, and show us how well they've engineered the vehicles. Etc etc; we've all seen it. And then they turn around to tell us everything we do (drive in dust, stop and go, cold and heat, towing) is "severe" and not "normal". Really? If that vehicle is so wicked-tough, they why is my typical daily life so freakin' extreme that I need to cut my OCI in half? Cannot the OEM design their rig around my seemingly mundane life? I'm so unique in my live-a-day world that they cannot accomodate my life as "normal"? Come on now ...
The reality is that "severe" definitions in the OEM manual are there to limit their warranty liability, and the broader they make the terms, the less exposure they have. It has nothing to do with the reality of how we live, drive and survive. And I've got the UOAs to prove it. In fact, so do most of you, also.
My pet-peeve is that the industry defines "normal" as conditions that hardly anyone ever qualifies for, but they want us to believe that they are sellling us a product that is engineered to conqour any challenge with the greatest of ease, in any environment.
So, coming full circle, I see this response from Amsoil as totally understandable, and it is a hybrid blend of their warranty embedded into the OEM warranty. Amsoil makes fantastic products, and they often can excel way past where most folks would dump them, but even Amsoil feels the compulsive obligation to limit their applications so as to confine their exposure.
