Examine away ..... you will find that standard Castrol GTX (all weights) is now a SN dino car oil, and specs exactly what the sorry Edge stuff did as it turns out it too
is a standard SN car oil.
Nobody does VOAs on Castrol GTX as Castrol says
up front what it is ..... a "sludge resistant" SN dino car oil.
Art, you need to click on the links provided in these discussions and READ what they say.
Now, Stinger and his high mileage bike. We have done this already, with both Stinger and WD. Here is what we found last time around the Stinger/WD barn.
He used different brands of oils at different times. Both like Harley weight oil because that is what they have always used. Some of his oil changes (I guess you could say most of them) were done a long time ago --- back when all oils
all had significant amounts of ZDDP in them. Thus he got what everybody got back then, adequate ZDDP to keep his valve train happy.
Now he's not getting that, but since the name on the jug stayed the same he considers it all good to him. I think he's in error about that lately, but it is his bike, now isn't it?
Next, Stinger has been around this barn before and isn't likely to want to go do it again. He just tosses out a Billish sort of statement and leaves.
WD's Savage bikes have all died electrically and been replaced (except maybe one, the one up on the cinderblocks).
If you want to play Stinger for him, that's fine ---- but you are the one making big assumptions about an oil and a situation that you can't even put a bottle type and a weight to.
Castrol is just a brand name, one that has been moved around all over the place by British Petroleum, who owns it now.
And, having been around the Stinger barn before, I can say he's had his bike a while and puts a lot of miles on it and he changes his oil regularly. Good for Stinger. Most of his Castrol used in his bike was probably built by Castrol Company using domestic American crude oil as the base stock.
There is a wide range between optimum and adequate --- if you keep any sort of oil in your bike and change it normally, you will get normal performance and normal life.
Do you want your Savage to need a major rebuild around 60,000 miles? I think most of us might could use some new rings about then, but replacing the cam and tappets doesn't have to be. Good levels of ZDDP cuts down on ring and cylinder wear too, BTW.
Savage Rob and some of the old guys have had to rebuild their engines totally and replace their cams and tappets at normal mileages using normal car oils from back in the day -- we try to do better than that now days.