Oil viscosity and spec high zinc?

[pete roper]

Just as a point of reference I had a customer I sold a new 8V Griso to way back when. It got its first service and its 10,000km service with me and he then moved away and there was nowhere nearby to service it. Now he really is a mechanical neophyte and didn’t to anything to it. He got in contact with me a few years later and asked if he could bring it in for a service, I said yes of course.

Anyway when I was working on it I noticed the engine was absolutely filthy on the inside! What I drained out of it was absolutely gross! When he picked it up I asked him when he’d last changed the oil. He looked kind of sheepish and said “Never, I just topped it up when it dropped off the stick!” At that point it had done nearly 90,000 Km!!!

Thing is, apart from being filthy everything else that I could check seemed fine! I got the chance to explore further about 30,000 Km later when it dropped a valve and destroyed a head, barrel and piston but whether the guide wear that promoted that was related I have no idea, the 8V’s do use valve guide oil seals after all. The whole engine as in remarkably good shape!

The long and the short of it is Guzzis tend to be monstrously over-built and modern oils are very, very good at their job and last extraordinarily well. I have always used Penrite 10/60 in everything I’ve owned built this century and nothing has blown up yet. That seems like a good enough reason not to change. To my mind the 10,000km service interval is very conservative but draining the gribblies out is always good, it’s not particulates generally it’s the crap and byproducts of combustion that need to be got rid of.

[PJPR01]

Has anyone just ran flat 30W oil for an oil change in a CARC bike and noticed any difference in performance?

In the garage for the various cars, I have a collection of Advanced Full synthetic Mobil 1 10W-30, 20W-50, 10W-40, 0W-40 and of course 10W-60, all full synthetics.  I'll try some experiments on using them in the Norge over time and see how the bike feels/behaves.  Good to know there are these options available

[gstallons]

If you ran in a perfect 70deg.+ temp you could get by. But then you would have to find a new "concern".

[docc]

8 minutes ago, PJPR01 said:

Has anyone just ran flat 30W oil for an oil change in a CARC bike and noticed any difference in performance?

In the garage for the various cars, I have a collection of Advanced Full synthetic Mobil 1 10W-30, 20W-50, 10W-40, 0W-40 and of course 10W-60, all full synthetics.  I'll try some experiments on using them in the Norge over time and see how the bike feels/behaves.  Good to know there are these options available

I use Mobil-1, too. Not in my motorcycles. Where do they declare their actual base oil? If the base oil is not Group 4 or Group 5, the motor oil is not "full synthetic" in spite of the marketing statement on the face of the label.

I've abandoned popular oils because the manufacturer will not provide the specification if the base oil.

[Lucky Phil]

3 hours ago, docc said:

I use Mobil-1, too. Not in my motorcycles. Where do they declare their actual base oil? If the base oil is not Group 4 or Group 5, the motor oil is not "full synthetic" in spite of the marketing statement on the face of the label.

I've abandoned popular oils because the manufacturer will not provide the specification if the base oil.

Here's what AI says about M1 oil docc. I always known it as a Group 4 full synth motor oil. It may have changed in the last decade, not sure.

Yes, Mobil 1 is a synthetic motor oil that uses Group IV PAO (polyalphaolefin) base stocks, often combined with Group V (ester) base stocks for its tri-synthetic formula, providing high performance and engine protection. While the specific formulation can vary, Mobil 1 is recognized for using these higher-grade base oils to achieve its "fully synthetic" claim. 

Phil

[pete roper]

Lard! Lard is good!

Actually lard is a fantastic lubricant. All animal fats are. The problem is most of them aren’t liquid at room temperature and they get smelly real quick!

One thing they keep very quiet is that sperm whale oil is still used as a lubricant in space vehicles because of its abilities to withstand extremes of circumstance. At least it was at the turn of the millennium. I have to admit I haven’t kept up…... 

[Randy]

I'm running Royal Purple HFS 20W-50 in my flat tappet bikes. It's formulated for those.

 

[Pressureangle]

47 minutes ago, Randy said:

I'm running Royal Purple HFS 20W-50 in my flat tappet bikes. It's formulated for those.

 

That's actually my first go-to if it's available where I need it. That's in the Bimmer at the moment. 

[Pressureangle]

On 9/19/2025 at 5:26 AM, pete roper said:

Lard! Lard is good!

Actually lard is a fantastic lubricant. All animal fats are. The problem is most of them aren’t liquid at room temperature and they get smelly real quick!

One thing they keep very quiet is that sperm whale oil is still used as a lubricant in space vehicles because of its abilities to withstand extremes of circumstance. At least it was at the turn of the millennium. I have to admit I haven’t kept up…... 

History is always fun, funny, and maddening. Lard is good.

(From Snopes.com my fav propaganda site)

"Crisco wasn’t invented by or for the German Navy, or for the purpose of lubricating submarines. Hydrogenation, the process by which Crisco is made from vegetable oils, was invented by German chemist Wilhelm Normann in 1901. Whether Crisco or similar products were ever used as submarine lubricants remains undetermined."

"Wilhelm Normann, eventually sold his patent to Procter & Gamble for use in the food market."

[gstallons]

OMG . I used to have to listen to this enlightened idiot that used to tell the margarine/submarine lubricant story all the time. He was the only one of us that was "in the know" and we were a bunch of banjo playin' hillbillies .

[Pressureangle]

40 minutes ago, gstallons said:

OMG . I used to have to listen to this enlightened idiot that used to tell the margarine/submarine lubricant story all the time. He was the only one of us that was "in the know" and we were a bunch of banjo playin' hillbillies .

lol those things are not mutually exclusive.

Lard, FWIW, was traditionally used to lubricate wooden wheel axles. So eating lubricants isn't off the table. No pun intended but I'll take 'em where I find 'em. 

Maybe that hovering dictatorial moderator will put these posts in a "Tin Foil Hat" thread. 

[docc]

Hey! I resemble that remark!

[gstallons]

I do solemnly swear        to never mention him again !

[Lucky Phil]

On 9/19/2025 at 8:45 AM, audiomick said:

So, thanks for the last couple of posts. As I wrote further up, I have decided on the strength of a Guzzi bulletin from some time ago to put 10W60 in all three of mine. The last couple of posts have further confirmed this decision. Why? I don't do an awful lot of miles, I do ride all year. That means also at temperatures around 0°C plus/minus a couple. I do ride more short trips (to work and back) than I do trips out of town. But the trips out of town do happen. So I want a wide range to cover the short, cold trips and the longer trips where the motor gets hot. And I'm not about to start changing the oil twice a year to cover winter conditions differently to summer conditions.

So, a wide range oil. If I ever find a 0W60 I might give that a go too.

If anyone can see a fault in my logic, I'd be glad to read it, but the argumentation needs to be good. 

PS: that it is necessary to keep the oil-change interval well within bounds is clear. I've ordered a round tuit to that effect. 

Well just because the manufacturer tells you to run a certain grade and sometimes even a particular brand of oil doesn't mean it's the best solution. To start with manufacturers can "align" themselves with oil manufacturers for fiscal reasons and then make their recommendations fit what the oil manufacturers makes at that particular time. There also a whole host of other reasons manufacturers specify a particular oil. So in my BMW powered Supra BMW specify 0W-20 oil. Why? partly because of it's ability to meet emission requirements at the expense of long term engine health. Do I run 0W-20 oil in it? No. I run a 5W-30 oil. BMW also fit the car with a city start/stop system to meet emission specs at the expense of long term engine health. Do I switch that shite off every time I drive the car? You bet your life I do. My previous Focus RS specified a 10W-40 for Australia and a 10W-50 for the USA. Why would you do that for countries with basically the same maximum daily temps in summer and much the same driving conditions. For "other" reasons is why. So manufacturers specify oil for a whole raft of reasons, some of which make sense only to them and also to cover every possible scenario their product will encounter. That's where being educated in the technical stuff and your specific operating needs comes in. If you have some detailed knowledge of engines and oils you can eliminate the political and peripheral rubbish and make an informed choice based on sound knowledge for your application.

Add to that the fact that oil specs are changing and evolving all the time and quite rapidly so some bulletin from Guzzi 10 or 12 years ago isn't necessarily worth squat today because oils have evolved a lot in that time. So as an example oils have recently gone from SN+ to SP rated. The SN+ was an interim spec oil to combat DI engines propensity for LSPI failures. It was then replaced by SP which then covered the LSPI issue and in addition gave extra cam chain wear protection so SN+ is now defunct. If you want to run the best oil in your engine then you need to keep up with the oil tech and not outdated requirements from manufacturers that were established for often spurious reason for their benefit not the owners. Remember the engine manufacturer has zero concern for the health of you engine once the warranty period has expired and even less(-0, lol) beyond that.    

In addition we now have bespoke oils for specific applications from boutique oil suppliers and that adds another dimension to the equation. So the owner has a choice of oil that narrows down to a specific engine configuration and type.

These days even brand specific dealers often don't use the oil spec specified by the vehicle manufacturer. It's quite common to look at your billing and see an oil grade other than the vehicle manufacturers requirements. Why? because if the specified oil is something they can't or don't buy "bulk" then they just use whatever they have! I've seen this many times. I'll bet you won't get a 10W-60 in your Guzzi at every Guzzi dealer there is.

So Mick I put the manufacturers recommendations on oil in the "for the guidance for the wise and the blind obedience of fools" category. 

Phil

Edited Saturday at 11:10 PM by Lucky Phil

[pete roper]

Took our new Hyundai in for its first oil change/10,000km service last week and they stuck a 10/30 in it rather than the 0/20 specified. My only concern was if it blows up will they honour the warranty? Since it’s all done through the ‘Official’ network they’d damn well better! I have ZERO interest in doing anything to this vehicle beyond topping up the screen washer bottle so if it shits itself and there are any issues it’ll be off to the courts toot-sweet!