Originally Posted By: Merkava_4
Both cars have the same exact engine.
I'd just attribute that to evolution of oil quality and evolution of manual wording. There is always plenty of bureaucratic inertia when it comes to altering things in the manual.
Originally Posted By: Shannow
I guess that it would be also only fair to limit the discussion of uber VI, thin oils to the PCMO portion of the board....
That needs its own separate thread like GC.
Originally Posted By: y_p_w
I remember there were some cars that only specified 10W-30 or heavier weights, such as the Acura NSX or the Honda S2000. There are still a lot of cars on the road with 10W-30 as the preferred weight. That might not mean a modern 5w30 wouldn't work just fine, but most people don't tinker with that.
I think that's the best characterization so far. Just because most of us here might think 10w-30 is superseded by 5w30 in just about every conceivable application doesn't mean that the general public would even consider the switch.
Originally Posted By: supercity
Maybe in America where they are the same price. But how would your opinion change if 5w30 was generally 50% more expensive?
Exactly. Up here, rollbacks on conventional tend to include 5w-20, 5w30, and 10w-30, so 10w-30 is rarely cheaper, unless it's the last stuff left on the shelf at a big sale. On occasion, though, I have seen 10w-30 excluded from sales, but that's uncommon. Shops sometimes still get a better deal on 10w-30 over 5w30 in bulk.
Much of this talk of obsolescence goes to semantics. It's obsolete in that there are really no applications where a 10w-30 is absolutely necessary and you cannot choose an appropriate 5w30 or 0w-30 (or even more obsolete SAE 30). But, that argument gets circular in a hurry, since a 0w-30 or a 5w30 can be replaced with a 10w-30 and the world won't go boom.
I rarely pick up 10w-30. There's some in my F-150, and that's a legacy of a situation I described above. The QS sale was too good to pass up, but someone already cleaned out the 5w30. From an "obsolescence" standpoint, I have no reason to buy 10w-30. It would work fine in either of my vehicles (or any of them I've had for years). But, if they're outside in the winter, 5w30 is preferred. There's no disadvantage to running the 5w30 in the summer, so eliminate the seasonal oil change and run 5w30 year round.
If they yanked every 10w-30 SN/GF-5 oil off the shelf, it wouldn't hurt my feelings in the least.