Originally Posted By: SilverSnake
I am always amused at the posts by those that just bought a new vehicle and immediately question the lubrication specifications/requirements and change intervals listed in the owner's manual. Many think that these requirements or recommendations have to be some sort of conspiracy by the vehicle manufacturer's and oil companies to cheat the customers.
That might be true, but there are many BITOGers that are quite capable of reading between the lines, as it were, on various pieces of equipment, especially ones that have what we'd call legacy OCI recommendations. Take a look at my G37's recommendations, for instance. It simply calls for an SM 5w-30, not even SM/GF-4, with a severe service interval of 3750 miles. Obviously, that OCI and service category combo is tailored to running the most basic 5w-30 out there, and one gets the good and the bad with that. One gets the benefit of being able to run just about anything in it, without having to buy something expensive, but, on the flip side, is expected to keep fresh oil in it. Obviously, there's room for prudent extension of an OCI.
The same applies to the early 7.3 Powerstrokes, with 15 L sumps and 3,000 mile OCIs. On the other hand, the old Audi had a 12,500 km severe service interval, and that's with ordinary, SJ conventional. That seemed a tad optimistic, and that wound up being quite true, with some of those matters creating a rather large Charlie Foxtrot for VW/Audi, which led to proprietary oil specifications based upon ACEA sequences.
In the end, OEM OCI recommendations aren't always as well engineered as we think them to be. We might have a company looking to extend OCIs on the basis of reducing maintenance costs, or we might have a company following the glacial pace of change, as Joe mentioned.
I'd be watching Nissan/Infiniti over the next few years with interest. They're beginning to promote more 0w-20s, but keep 5w-30 conventional as a distinct, approved option in their manuals, with OCIs ramping up to 10,000 miles in some cases. With respect to the new Q60 with the 400 hp 3.0 turbo that Infiniti desperately wants me to buy, I'm not exactly sold on the idea of 10,000 mile OCIs with 5w-30 conventional, which falls within their warranty requirements.
3750 miles with Mobil 1 EP would be almost certainly overkill. 10000 miles on Mobil Super conventional is almost certainly overly optimistic, and I gather that Infiniti is banking on a lot of people using premium oil and going to the dealer for early, frequent, upsold oil changes.
