Originally Posted by StevieC
The diminishing returns aren't realized until way way way after the junk points of most vehicles. There are high milers right here on BITOG that have done it on 20 weights. PROOF!
I wasn't arguing that their isn't increased wear, just that it's a non-issue in the majority of cases even well out to a really high mileage so why change to a 30wt in fear, especially in Alberta winter where it could be counter intuitive.
We have to be cautious about where, however, those diminishing returns become seriously problematic. I do have some faith, however, that warranty actuarials will keep some of that in check. Me running a 20w-50 or an SAE 40 in my G37 where a 5w30 ILSAC is perfectly acceptable will save more fuel than me dropping from a 5w30 ILSAC to a 5w-20, and in that engine, I'd start to worry about wear. Clearly, not every engine specifies a 20 or is backspeced to one, either.
So, the concerns are absolutely real for certain platforms. From a non-technical perspective, again, people do see that and tend to worry. From a technical perspective, though, it's all been spelled out here fairly well, and we all nitpick about certain things. You're clearly worried about wear. You drive a bajillion miles a year. You're looking for better filtration. You're running a premium oil. You use a catch can. You take meticulous care of your vehicles.
Some guys use block heaters in the summer. Others are concerned about higher HTHS. Others are looking for higher additive levels.
Lower HTHS certainly has tradeoffs, and note that some of those tradeoffs are good. Each time an oil specification gets thinner, people will be concerned. At one point, however, for each vehicle, there is a tipping point. I'm not terribly thrilled with the idea of abandoning parts separation even more to slide along the Stribeck curve.
What really picks my behind, and I'm sure it does with many BITOGers here, is that OEMs treat us like darned fools. As I pointed out, though, that applies to most of the oil buying public, so we're collateral damage.
No, a 15w40 isn't going to make a Dodge gasser explode, contrary to what the OEM would have us believe. No, a 0w-20 won't hurt my G37 in a Saskatchewan winter, particularly the way I drive, despite the 5w30 recommendation.
