Originally Posted By: Garak
Originally Posted By: fdcg27
I hate to be pedantic, but you are using 10W-30 in one of the vehicles in your sig. Could 10W-30 actually offer some advantage over 5W-30 in a specific application, and are those advantages as relevant today as they were in 1985?
That was on a special I couldn't pass up, and they were out of 5w-30. There's certainly not anything inherently wrong with the grade. I've used it for many years in fleet usage. It's just that 5w-30s have improved. And a 10w-30 being rather obsolete doesn't mean it's useless or flatly inappropriate.
As for potential benefits, of course it's possible. However, 5w-30s are far more shear resistant than they used to be, and that's one of the reasons the 10w-30s were favoured years back. In my fleet usage, I could have probably gotten away with straight 30, given the lack of cold starts.
One potential benefit may be if someone is looking for something with higher ZDDP in a 30 weight, and goes for a 10w-30 HDEO. That would be useful in my old truck.
With respect to the original poster's question, I'd say it's "fine" but not "optimal." My old Audi speced 10w-30 way low, and so does the old F-150. Given the oils of the time, they made the best recommendations they could. So, if I find it on special again and nothing else is available, I'd use it. I wouldn't go out of my way to find it. What's in the F-150 is my last jug, by the way.
Originally Posted By: gfh77665
My point was not about Thick vs. Thin, but how rationale is so inconstantly applied. Some think Chrysler calling for only 10-30 is stupid, while they would praise and gush about Ford for their 5-20. Peoples minds aren't open viscosity wise.
Well, speaking of rationales, we do know what the rationale is for a 5w-20. There are CAFE requirements and indications they can protect just as well as a 30 weight.
We don't know the rationale for the 10w-30, and that's the problem.
That being said, I'd stick to what was recommended in the manual. I think it's a strange choice by the manufacturer, but they provide warranty coverage, not me.
I believe the rationale was that in SF and SG days oil used to not be as good, and 10W-30 would hold up better than 5W-30. Now those days age gone, sure.. but are we talking about the 80s? My folks liked 10W-40 because of the quality of the oil back then. Used it in winter too
I am unsure why the "0" W number is not sought, followed promptly by the "5" number nowadays. 0W-30, 0W-40 etc. I know HTHS makes some cars "HAVE" to have a 5W-30.. even then, i wonder what would happen if a 0W-30 went in.
CATERHAM? What can happen if an oil has a lower HTHS than a manufacturer specifies? (Dare i say it.. "too thin?" Im thinking of 0W-30 Redline where 5W-30 Redline is what people use, specifically. On the non-10W-60 spec'd engine.)
