10w60 or 10w50

[Old Jock]

I've no desire to keep the thread alive particularly

But just an answer to the 2 numbers the W stands for Winter and is viscosity at 0C, the other number is the viscosity at 100C, so close to what the oil will be running at inside an engine at operating temp.

So looking at any given multigrade, 10/40, 10/60, 20/50 etc: it doesn't really matter regarding the relative behaviour of any given multigrade. The oil at 0C is, of course, is thicker than when the oil is at 100C, multigrades slow the thinning of the oil as it get hotter, so a straight 10 for instance would be a lot thinner than a 10W/40 at 100C.

The bigger the difference in the numbers the less change in viscosity takes place, so a 10/40 will be thinner at 100C than a 10/60, which is stating the obvious but just spelling it out. Oil companies use Viscosity Index to show this, the higher the VI number the less change in viscosity occurs as temp is increased, but I know next to nothing about VI.

The other point worth noting that some may be unaware of, I certainly wasn't until recently, is visocosity change with temperature is not linear, but logarithmic, the relationship's a curve. The hotter the oil gets, the smaller the difference will be between different grades.

It's also worth remembering that a graph can be made to accentuate a particular property depending on the range chosen for the relative axes.



It's a complex topic, hence all the debate I suppose and I know little about it, but I thought I'd share my general ignorance.

John

[bad Chad]

I can only add that I was told by Jim Baron, one of the elite Guzzi techs in the world, that 10w60 was as near critical for long health engine life on 8v big blocks.   And while not an absolute must for modern 2v Guzzi mills, it is definitely the best choice for those as well.

[SmithSwede]

I don’t have hard test data to disagree, but I am curious about the small blocks and the supposed necessity of a 60 weight oil for everyday street riding.   

I get it for the big blocks. The modern 8 valve big blocks are cooling the exhaust valve area with the oil, and were presumably designed with a 60 weight oil in mind, along with an oil cooler.   

But the small block seems to be a very conventional engine design, much like a BMW airhead
or air-cooled Ducati.  Nothing tricky is being done with internal oil cooling.   The engine was designed long before the  ready availability of 60 weight oil.  Earlier manuals all specified a 50W oil.   

I have a strong hunch that once Guzzi was required to spec a 60 weight oil for the big blocks, they said screw it, make that the standard for everything.   Which won’t really hurt anything.  My hunch is a small block would be just fine running a high quality 50 weight. 

I could be wrong.  Would certainly like to see hard tribological data on this, or hear a good explanation for why a 45 horsepower 750cc air-cooled small block really needs a 60 weight oil. 

[Brand X]

I can only add that I was told by Jim Baron, one of the elite Guzzi techs in the world, that 10w60 was as near critical for long health engine life on 8v big blocks.   And while not an absolute must for modern 2v Guzzi mills, it is definitely the best choice for those as well.

A tag under the seat of my 2007 Breva 1100 say 10w-60. Different from the factory old spec 5-40.. I had some high quality 15-50 I used to flush out the what was in the Bike. Just used it for some wintertime rides, and run only 10-60 top spec oil..

I am a huge fan of Ester based 10-60. It will handle the heat better then any other oil..Any good quality oil will work well in these Motors, but having one that I know worked well in my 1100 Ducati, and Water cooled V-twin 990 Rotax's confirms my choice..

[moto-uno]

The "W" simply stands for winter "freezing temp of water",0 degrees celcius , the higher number refers to it's viscosity
at the boiling temp of water , 100 degrees celcius . Those were the old SAE standards for measuring viscosity . Oil at 0 degrees
is passed through an orifice for a length of time and measured , the same is done at 100 degrees C and measured , what ever
range that falls under gives you their viscosity . All the additives etc are another very long story that seems to evolve annually.
Peter

[ozarquebus]

I thought I was the only one who loved mixing different weights of oil for fun.
 I especially like the 12.5w 55 synthetic blend with Marvel Mystery oil.

[Vagrant]

Thank the good lord I had just poured 5 fingers of fine 10/60 Scotch before starting to read this thread.

[kballowe]

BelRay 10W-50 is what goes into your Guzzi at our local dealer.

[Perazzimx14]

The 8V 1200s, are Oil Cooled Engines (as all 'Air Cooled' Engines are really).
The Cooling Circuit Oil is pumped straight into the Heads, to flood the areas around the Exhaust Valves, and it gets extremely hot in there.
That's why the -60 Fully Synthetic is specified.
I wouldn't risk -50 in my Engines, under any circumstances.

At the 'other end', I'd never hesitate to use a 20W-60 in Summer.

You can get Mobil 1 in 10W-60, some BMW cars use it, it's reasonably priced, and should be available pretty much everywhere.

Remember we can use car Oils in our Guzzis (Dry Clutches), so you don't have to fork out over-the-odds prices for Bike Oils.

Me thinks you have Castrol and Mobil mixed up. At least in the USA there is no 10W-60 Mobil.

If it works for you Mobil 1 15W-50 synthetic at MaoMart is $25 for 5 quarts and usually from April - October there is a $10 rebate (two per household) making a quality oil very cost effective.

[Brand X]

Thank the good lord I had just poured 5 fingers of fine 10/60 Scotch before starting to read this thread.

Crap, it now turned into a ethanol thread..

[mr_pacman]

Motul 10w60 seems to be readily available around here. The only oil you can really find in that weight from a retail store. I never considered the BMW dealers but my old M3 was required to take 10w60 so that's a great idea.

[dirtiegirtie]

I'm gonna need some help. I just did my first oil change. I was instructed to use 1.5L of EVOO in my 2015 V7. Does it need to be Extra Virgin Olive Oil or will any Olive Oil do? I just ask as that 'first press' crap is expensive!

[reidy]

I have never jumped in on an oil thread before, but they say you should try everything once.

Ever motorcycle I have owned has a range of oils that are suitable and this is linked to what temperature range the bike is likely to operate in.

A bike that is used in a cold Canadian winter will need a different weight oil to that of a bike in outback Australia in summer.

Oil gets thinner, or more runny or to me more correct, less viscous as it gets hot. When you start your bike you want the oil to be thin enough to circulate quickly and buildup pressure to protect your engine. This is the first number 0, 5 , 10, 20w and such. If you live in a very cold area you will need a very low number. This number is measured at 40 degrees c.

The second number is the viscosity when the oil is at 100c. So straight weight oil is a constant viscosity. Multigrade sort of works like two different lots of straight grade. That is it keeps a more constant viscosity as temperature changes. The higher the second number is, the thicker the oil is at 100C. Earlier a graph was shown how this works. I should point out that this is the temperature of the oil not the outside air. Now if we are riding in Canada in mid winter our bike won't heat up much and we will want a lower number so the oil is not like honey. If we are in the Australian summer we want a high number so the oil is not like water as the engine will be very hot. 

Now the clever engineers have calculated bearing clearances, oil pump size, expected engine oil temperature and such and have determined how thick the oil should be in the operating range. There is a range that is ideal so we don't have to change the oil from the cold morning to midday. Also as an engine wears a slightly heavier oil is required because the bearing clearances open up creating less back pressure and needing a thicker oil. 

Now for my opinion. Oil has always been used to cool your engine. It is now used more in some applications to cool around the exhaust port. This puts more heat in the oil and thins it out. I would suspect that Moto Guzzi has noticed in some hot climates the extra heat the oil is taking from the motor is causing the oil to thin more than the ideal. Therefore they have recommended a 60 as an extra safety margin.

For most users who use their bikes in the middle of normal temperature ranges and ride their bikes as the maker intended there is a lot of latitude to oil weight as shown in the owners handbook. 

Now for my recommendation pick an oil you like tat meets the specifications from the manufacturer and use it. I use Penrite for the following highly scientific reasons. It is an Australian company and I like to support Australian companies. It is widely available so I can easily get it when I need it. It meets the specifications in my owners handbook.

Steve

[dmcdonaldjr]

Sloan's did the same on my first service and oil change yesterday (10w50)... Thanks for the comments, I'm going to run it to the next change on my 2020 v85

[Amstaff]

I don't know why this topic comes up. Amsoil, BelRay, Motorex, Motul, Castrol and probably others still make 10w60 oil. Couple of years ago got a case of ENI (formerly Agip) but they said on the phone they got out of that business.

[Xlratr]

The 8V 1200s, are Oil Cooled Engines (as all 'Air Cooled' Engines are really).
The Cooling Circuit Oil is pumped straight into the Heads, to flood the areas around the Exhaust Valves, and it gets extremely hot in there.
That's why the -60 Fully Synthetic is specified.
I wouldn't risk -50 in my Engines, under any circumstances.

What John Warner said. The ambient temperature isn't really the issue here, it's what's going on around the exhaust valves in the 8v engine. Of course everybody is free to do what they want with their own motorcycle but if a dealer put 10w-50 in my bike I'd change it 5 minutes after getting home and never go back there again.

[hzbloke]

I have never jumped in on an oil thread before, but they say you should try everything once.

The advice actually is "You should try everything once except incest and folk-dancing". If the bloke who said it were alive today he would probably add 'oil threads'.

[aklawok]

I've seen the tech paper from Guzzi at Hamlin's shop. 10-50 has been superseded by 10-60.  Wanna read the manual?  There it is.

did you mean 10-60 has been superseded...not the other way round? fishy... would like like a linky if you got one! 

[Sye]

Manufacturers spend big doing the R&D and tell us what weight and spec oil to use. It's important that it meets both specs. Mine says:

Engine oil 10W-60 JASO MA, MA2; API SG - Synthetic based lubricant for high performance four-stroke engines, so that is what I will use, simple.

[mechanicsavant]

Mr. Hamlin has not misdirected me yet ! And yup , I’m using liqui-moly oil from NAPA

[Stratodisaster]

Why do so many people have a problem just using what the owners manual recommends.Wouldn’t that seem like the most reliable source of information?

[Old Jock]

Why do so many people have a problem just using what the owners manual recommends.Wouldn’t that seem like the most reliable source of information?

Well yes, that's one way of looking at it.

Then there are some like me who will experiment a bit, due to issues or some more investigation

Take my HiCam engine as an example, it runs helish hot, 110C in free air, in the town that will quickly rise, I've seen 130C oil temp.

The oil recommended for that bike is 20-50, back in the day when 10-60 was not an option.

I'm currently running a 15-50 with a Griso spring in the PRV, as the original partly lifts and robs the bike of much needed pressure.

The 15-50 is thinner than a 20-50 for starting and a 10-60, because when I start the bike it will be nearer 20C not 0C.

I'll probably end up going to a 10-60 as many HiCam owners do, due to the hot running reducing viscosity and dropping the pressure. I'd prefer to reduce the engine temp and still run my 15-50, if I can and looking into that.

All I'm saying is it often isn't as clear cut as it seems and when looking at oils and viscosity the best approach is to actually look at the manufacturer's data for the brand in question.

The viscosity can vary quite a bit, brand to brand for the same grades. So unless you're running not only the viscosity rating but the actual recommended brand, you're probably not running exactly what the manufaturer states.

In my Ducati 1098 I ran a 15-50 as most people on the forum I was on did too, the 10-40 recommended made the gearbox sound horrible.

Each to their own, if sticking to recommended grade is what you want great.

However those of us who choose not to are not necessarily idiots and often have very good reason.

[Advguz]

10w 60 Motul

[Amstaff]

Greater viscosity is thicker and has a higher number. Yeah, I though one previous poster wrote the opposite-high viscosity is thinner…. Nope.

[Stratodisaster]

Well yes, that's one way of looking at it.

Then there are some like me who will experiment a bit, due to issues or some more investigation

Take my HiCam engine as an example, it runs helish hot, 110C in free air, in the town that will quickly rise, I've seen 130C  you probably don’t take it to a dealer for something as simple as an oil change. I’m not implying there’s anything wrong with what your doing what I’m saying is why,if you lack knowledge why would take the word of a bunch of people on a forum or some goof-ball at a dealer over what’s written in the manual.

The oil recommended for that bike is 20-50, back in the day when 10-60 was not an option.

I'm currently running a 15-50 with a Griso spring in the PRV, as the original partly lifts and robs the bike of much needed pressure.

The 15-50 is thinner than a 20-50 for starting and a 10-60, because when I start the bike it will be nearer 20C not 0C.

I'll probably end up going to a 10-60 as many HiCam owners do, due to the hot running reducing viscosity and dropping the pressure. I'd prefer to reduce the engine temp and still run my 15-50, if I can and looking into that.

All I'm saying is it often isn't as clear cut as it seems and when looking at oils and viscosity the best approach is to actually look at the manufacturer's data for the brand in question.

The viscosity can vary quite a bit, brand to brand for the same grades. So unless you're running not only the viscosity rating but the actual recommended brand, you're probably not running exactly what the manufaturer states.

In my Ducati 1098 I ran a 15-50 as most people on the forum I was on did too, the 10-40 recommended made the gearbox sound horrible.

Each to their own, if sticking to recommended grade is what you want great.

However those of us who choose not to are not necessarily idiots and often have very good reason.

[Old Jock]

I’m not implying there’s anything wrong with what your doing what I’m saying is why,if you lack knowledge why would take the word of a bunch of people on a forum or some goof-ball at a dealer over what’s written in the manual.

Oh my bad if I misinterpreted your meaning, I agree if you haven't done any research or cannot be bothered, then yes stick to the grades recommended in the book.

I'd never take anything on here or elsewhere on the Interweb as gospel unless I could follow through the logic and reasoning myself.

Greater viscosity is thicker and has a higher number. Yeah, I though one previous poster wrote the opposite-high viscosity is thinner…. Nope.

Not sure if that was directed at me when I said, "The 15-50 is thinner than a 20-50 for starting and a 10-60, because when I start the bike it will be nearer 20C not 0C."

Yes as oil grade numbers get higher the oil gets thicker, but only at the specified temperatures, which are 0C and 100C.

At intermediate temperatures, it's not uncommon for grades which on first glance you'd think are thinner (or thicker) are very often not.

Multigrades with numbers closer together, will have a different curve to those with numbers farther apart and you need to look at the quoted viscosity in the spec sheet, normally quoted at 40C and 100C as I recall.

It gets worse as the most common formula used to interpolate the viscosity at intermediate temps, (well the only one I've found, Walther's formula) really only holds for Newtonian fluids and Multigrades depart from these rules.

Just saying as when I started to look into all this because of my "Red headed Step Child" HiCam engine, I found out viscosity vs temperature behaviour was far from straightforward, at least for one of my limited intellect

I cannot believe I'm still participating in an oil thread, as they all end in tears or the mods erasing them (usually with good reason)

[SIR REAL ED]

I cannot believe I'm still participating in an oil thread, as they all end in tears or the mods erasing them (usually with good reason)

Oh so true.  But it is like watching a car wreck in real time.  No one approves, but few can turn away before the impact.....

IMO that is what makes WG such a great site.  Everything from excellent information to technological nerdity and absurdity is featured. 

It is a one stop shop without equal.

Kudos to all who participate.

[Amstaff]

OJ,

I must’ve screwed up reading/remembering. Thats why I qualified it with ‘I though’…
Oops, I meant “I thought.”

[greer]

Had my first service at Sloans earlier this week, lubricants used were Castrol Power 1 4T 10W50 and Castrol Syntrax Long Life 75W140.  I'm more concerned about overfilling, I had an air gap in the upper part of the window prior to the service, none now.  I'm thinking I had the air gap from the beginning, but I may be wrong. 

Sarah

[jcctx]

I am no expert, but I REALLY doubt anyone will ever know the difference no matter if they run 10W50 or 0W60 after 100K Miles!!!!