The 10K looks better than the 20K, slightly higher viscosity, slightly higher TBN, even slightly higher flashpoint. Could they be roughly the same? Only VOAs on the same engine, under the same conditions & use, would really be able to show a difference.
The 20k probably has better viscosity stability. Meaning the 10k should work for 10k but after that the viscosity may start to thin out too much out of grade. Whereas the 20k, if we're taking it beyond 10k, should have the ability to keep the viscosity in grade for that longer interval. So that slightly lower visc on the 20k is a better choice in the long haul beyond 10k.
See the one example above. But I suppose it's base oil, VI's, along w/other things that set them apart. $1.51 extra for the 20k means we don't really have to struggle too much to decide LOL. IMO the 20k is the better choice knowing you want to er' on the side of caution & have a "Buffer". There are other variables, like oil grade etc., but that is not part of the discussion so I'll leave them out.
I am going to assume that the Kirkland oil is more along the lines of a 10k oil. They're not claiming "Advanced" Full Synthetic & claiming no mileage on their oil so more like a basic full synthetic. Also, the prices that you're quoting shows they are probably the cheaper option compared to the more expensive 20k SuperTech in Canada.It's definitely not a struggle deciding, it's just that the oil geek in me would love to know the full technical story on these oils
At the same time it has me curious, since we know that Kirkland's oils are also made by Warren, is their oil the 10k version or the 20k version? Kirkland oils make no reference on the bottles as to how long they are rated for. I'd love to switch to Kirkland synthetic because when it goes on sale up here it's $40 CDN for two jugs, making it an even lower price than what it costs me for Supertech (that jug converted to $28 CDN for me)
TOFTT would be running 99K with only 4 oil changes and then pull the valve covers for pics.somebody TOFTT and post a UOA.
Interesting to hear the differences just across the border. I hear you about the frustration. I'm a sponge by nature & love to soak up anything I can too. Sounds like you're better off buying from the US market since the bottles are labeled in mileage & would give you a little better idea of the quality you're getting.Our Walmarts in Canada only have one version of Supertech actually, and it doesn't give a mileage rating on it at all. So unless I continue buying my oil from my travels in the US (which is where I got the oil I'm running now) then I really don't know for sure what version I'm getting up here. All of this lack of information is definitely frustrating for an oil nut like me
