Royal Purple?

[Mr Gazza]

For many years I have used Castrol 1 power racing fully synthetic oil in the Monster and have sometimes wondered if I could do better?

Looking for a suitable oil to use in the old Commando, I have come across an exhaustive test on many oils by Jim Comstock, who tested all the oils with a real world application to Commandos in mind. https://www.accessnorton.com/Oil-Tests/NortonOil.php#9

Two brands that I had previously not heard of stand out, Royal Purple and Red Line. These are US produced oils.
I am considering changing to Royal Purple HPS 10w40 for the Monster.
Obviously the needs of a Commando are a bit different to an air cooled M900 engine, but it does get very good reviews elsewhere too.

I wondered has anyone heard of it or has tried it and what you reckon to it?

[uncle duke]

An oil thread fantastic....... i must have used nearly every brand of oil in my Triumph TR6R over the years from Halfords own, comma, gulf ,silkolene .valvoline .penrite ,castrol etc etc & even wilkinsons !! but have ended up with Morris Golden film 20w/50 which seems to be a good oil at a very reasonable price ...i change the oil every 1000 miles anyway . My mate who has a 750 commando fastback as well as a few other classics uses it as well ...

[Mr Gazza]

Yes, I would agree to 1000 mile changes on an old parallel twin, even with a modern cartridge filter.
I used Castrol GTX for years until they changed from 20w50 and went to 10w40, whereupon I switched to Duckhams Q.

The Monster oil and filter gets changed every Winter regardless, based on about 4-5000 miles per annum, but I have a 6000 mile max in mind for the oil. I wondered if I could go two years with Royal Purple?

StevieL turned me on to Morris oils, He's a big fan of it, but so far I haven't tried any.

[Zimbo]

I quite like Morris oils for older machines, used to use the monograde SAE40 or 50 in the old Nortons I used to have (650SS and 750 Atlas motors) and still use it today SAE30 on my boat, which is powered by a marinised version of a Ford Anglia motor. I have never come across Royal Purple though!

[utopia]

Capo used to swear by Amsoil for his S4R.
I'm not exactly sure where he got his recommendation from but you can bet it was a technically competent source. I think there was an American guy, possibly called George, with lifelong experience in oil chemistry who used to post on one of the American ducati forums.
Me, I'm less fussy and stick with Shell Advance Ultra for my 750, but that's partly because I know its compatible with the wet clutch on my bike.
In any case, I like to pick an oil and stick with it for the long haul rather than chop and change at every oil change, my reasoning being that although modern oils of different brands are claimed to mix happily I feel that they must be better off if they don't have to.
This might be particularly relevant for bikes with an oil cooler because unless you go to the trouble of draining the cooler there will always be a decent amount of the old oil retained therein.
Capo of course always drained his oil cooler but I confess that I usually can't be arsed. Well to be fair, its also because my maintenance strategy nods toward not disturbing certain stuff (like oil cooler hoses with seals, or rubber mountings) unless you have to. ​But then again, I seldom run oil to anything like its maximum lifespan so even the old oil from the cooler is still likely to be decent. And I know it'll mix perfectly.

I'm kinda boring in my oil choices .... but not without good reason.
The mainstream, recommended choice is a safe choice that covers all the basics.
Its probably not the most expensive, so you can afford regular changes.
Its also easily obtainable and likely to remain so.
Also by sticking to one choice, there's no waste bits left over and easier storage too.
You'll probably not be surprised to hear that I have two bikes and I run them both on Shell Advance Ultra .. though again they both have wet clutches which this oil suits.

As a general rule, I'm happier with an oil produced by a big name manufacturer who has the financial clout to do extensive R & D, rather than a niche, little known brand.
For that reason I would naturally tend to steer clear of something called Royal Purple.

Though I heard that they recently changed their name and now insist on being called "The Lubricants formerly known as Royal Purple".

[Mr Gazza]

Thank you for a considered reply Jeff.
We think along very similar lines. I sat in the shed this afternoon and thought I might as well stick with the Castrol Power 1 as I have done for so long. In fact your comment about "Lubricant formerly known as Royal Purple" would be enough to make me boycott it completely.
I too have drained the oil cooler on occasion, but mostly can't be arsed. I do worry about the moments on first start up when the cooler is filling and not passing oil to the mains.

I think given the total lack of any wear problems in my engine, that I will just stick to the same oil.. And you have reinforced that view.

Comstock's tests were probably not relevant to a more modern engine anyway, but they did highlight some good and bad oils to use in Commando engines and for that matter many old twins.

I looked up Morris Golden film and noted that it is for "classic" engines with no filtration system and so is a very low detergent oil. My Commando is newly rebuilt and has a full flow cartridge filter, so I will going for high detergent from the start.

On another subject I have mailed Morris about their EP 80w90 for use in the AMC gearbox. There is a belief that sulphur in EP oils destroy "Yellow metals" which are very common in the AMC, and lots of other old British gearboxes. I bought the oil a long time ago before hearing the Sulphur/EP oil story, so I want to know if I can use it in my expensively restored gearbox... I'll let you know.

Thanks for all the comments.

[Mr Gazza]

Well Ryan, in the technical department of Morris Oils picked up his mail this morning and promptly replied to me.

He confirmed that the EP80w90 does indeed contain Sulphur as part of the extreme pressure additives and kindly recommended that I don't use that in my gearbox.

He put me onto Golden film AG90 which will be safe.

I'm impressed with Ryan and Morris Oils for a prompt and sensible answer.. Well done.

So there's a tip for you to pass onto your classic riding mates Roger. Drain any EP gear oil out of your gearbox immediately and replace with AG90 or non EP oil. I've heard that a lot of folk are using ATF (automatic transmission fluid) in gearboxes with success, probably better than dissolving the bushes?

[uncle duke]

Hi Gary great bit of work you've done there .I have used EP90 gear oils ever since i've had old triumphs (which is a few years !) & touch wood never had a problem with bushes or any gearbox problems , i did read that GL 5 is a no no as it contains more of the sulphur additives & that GL 4 is ok as its only at really high temperatures that problems can occur. I forwarded your piece from Morris oil's to the Commando owner & he straight away bought some AG90 & some for me as well !! so a big thank you for all your hard work & it's really good that Morris oils got back to you so quickly they seem to be the good guys . I use their 20w/50 Golden film as i haven't fitted a cartridge filter to my Tiger so a good 'classic' oil is a must .I hope to see your commando at one of the meets soon in the coming year .

[Mr Gazza]

Nice one Roger I ordered my AG90 this morning.
I'm glad I asked the question because I went and bought what I thought would be the best stuff assuming that GL-5 would be better than 4, 3 or 2.

EP90 was the standard stuff for most bike gearboxes and was recommended by the manufacturers, (as you know). It has only emerged since the "classic era" that the Sulphur eats the yellow metal (brassy metals). When you think about it those still about today could have been marinating in Sulphur for 40-50 years or maybe more, whether in use or not.
Over 40 years in the case of my Norton. I never had any bother whatsoever with any AMC gearbox when I abused Ajay's about thirty years ago, but when I rinsed out the complete 'box off the Norton prior to refurbishment, I got what I thought was a lot of copperslip out of it. My engineer mate, Hutch, said "That will be the bushes!" He kindly replaced all the bushes and did a needle roller conversion on the output shaft, so all should now be good.

[jerry]

I like Motul or Putoline for my Ducatis the S4 always gets Motul synthetic the aircooled ones get putoline semi synthetic always every year or 5000miles

for the old shovelhead its Morris straight 50

[utopia]

Originally Posted by Mr Gazza

Thank you for a considered reply Jeff.

Ah good.
I was a little concerned that my comments might sound a bit flippant.

I actually pondered the whole question of oil selection a lot longer than my edited reply suggests .. but if I'd posted all of my ramblings folks might have started to talk.

[Flip]

This has been an interesting thread for me too as a year ago I bought my new Moto Guzzi V7 and that has quite a 'car like' set up of engine (10w60), gearbox (75w-90) and final drive (75w-140), presumably all safe in their modern applications?

It got interesting as the oil partner for the Piaggio group is Castrol but the recommended 10w60 engine oil is not imported into the UK which means every main dealer is using another make-certainly the local Piaggio dealers near me selling Aprillia, Vespa, Moto Guzzi use Rock Oil, obviously as long as this meets the required standard it is fine but it did rather make me laugh when under the seat it has a label proudly stating 'Lubricated by Castrol'.

After a chat with Opie Oils technical chaps there were two options available for me, Motul and Silkolene with the Motul being the best option as apparently it's make-up is closer to that of Castrol.

This made me wonder how many other main dealers don't use the manufacturers recommended brand of oil as I remember years ago a family run Yamaha dealership (which sadly closed due to the corporate strings being tightened for them to conform to a uniformed showroom like all the other dealerships in the country) use to use Morris lubricants rather than the factory 'Yamalube'.

[Zimbo]

I seem to recall that at least one major Ducati dealership a few years ago was using Rock Oil in their service department.