Castrol 20w-50 in a '74 MKII?

Dommie Nator said:
I feel like I'm about to commit blasphemy but I'll post my experience anyway.
I tried some Royal Purple HPS 20W50 after it was acclaimed to be the "winner". Yes, it's purple and my immediate thought was that's surely an unnecessary gimmick?
After returning from the 2019 Begonia rally in Belgium and experiencing really hot weather I thought I'd check the oil. At this point it had been in the bike for about 800 miles, it smelt burnt and looked black so I decided to change it. Having warmed the engine I took the oil tank plug out and the oil shot out with the consistency of water, the tanked drained in seconds and as noted before, it smelt burnt and was black.
I replaced it with Castrol XL 20W50 but must admit to doing so because of, again, the influence of the Comnoz oil testing.
I've stuck with that though as at least it looks like oil and as it's more available and better priced so I change it often.
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This is an extremely interesting finding.

I’ve got RP in my Commando but due to the recent carb issues its done very little. It’s also in my T140 which is off the road currently.

Has anyone else seen this when changing the oil when using RP?

I have to say that I thought the same thing, there’s no way it can be purple by accident, that has to be a colouring, which can only be described as a gimmick.
 
I’ve got that Royal Purple HPS 20W/50 in a notorious cheaper marque of British 650 twin, with a cast iron head. The engine runs hot.

The oil has done about 2,000 miles, some slow, some fast. Nothing bad has happened to the oil. It does look black if you look down into the oil tank, but all oils do that. Yes, I’ve tried practically all oils!

If the oil goes thin and smells, consider that fuel may be getting into the oil.

At the end of the day though, if your Commando cylinder head is getting hotter than my T*****h one, your Royal Purple may be degrading where mine doesn’t.
 
I’ve seen green oil, red oil and now purple oil.

Yes it’s a gimmick, or a branding exercise.

It’s really purple, but is it really royal?
 
I ran Royal P HPS the last 1200 miles in my Rickman Enfield. The oil came out black as coal. Now granted, the Enfield doesn't have the best ring control. What bothers me is the purple part. You cannot see if the oil getting dark or not. Handy when filled with fresh oil as you can easily read the dip stick not so good as time passes and the oil looks dark rather quickly.
Is it working as "The Best Oil"? I don't know. Bike still runs! But then with 20-50 Klassic the cost per quart allows for frequent changes which is probably better in out mild climate.
 
I have been running my 99 on Yamalube 10/40 fully synth for some years after being gifted a few gallons . Summer and winter in the Uk . Local temps - 3 to 40 deg . Absolutely no swarf on the magnets engine very clean internally , Easy to kick over cold. Had a carb issue that got the motor so hot it would run with the ignition off ! , should have seized , but did not . Fully synth oil tech is very superior to old dino stuff. I would go with a fully synth 20/50.
 
I noticed the GTX Classic at Walmart and purchased some, It's been awhile since I've seen it for sale. That's all i use to put in my vehicle's back in the day.
 
I use the Green oil, Brad Penn, in single grade 40 weight. High zinc product. Recommended by an engine rebuilder I trust. Just piling on here...
 
Hortons Norton said:
I noticed the GTX Classic at Walmart and purchased some, It's been awhile since I've seen it for sale. That's all i use to put in my vehicle's back in the day.
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The gtx classic is actually a new product, but who knows, it may be identical to regular GTX from the 70s/80s.
I'm hoping this new stuff is low friction like the UK version.
The US / Canada regular GTX that Jim tested was extremely high in friction.
 
Jdub said:
I use the Green oil, Brad Penn, in single grade 40 weight. High zinc product. Recommended by an engine rebuilder I trust. Just piling on here...
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Been using 50W Green oil since back in the days when it was known as Kendall and now Penn Grade ........ 15 years ago the Kendall was $2 Cdn a litre , now , $ 12
 
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