Oil Viscosity

[manxman]

Can anyone say why so low a viscosity ( 5w) when most of these machines are ridden in plus thirty weather ? I doubt if the oil ever gets down to be as thin as 5w. Since it is obvious that it needs a 40 wt. for hot running, whats wrong with a 15w40 oil ??

[JayBros]

5W-40 just gives easier starting in cooler weather. It may or may not matter depending on where you live. The API sets the standards so a given oil can have the widest possible range of geographic use. If you notice some cage oils are now 0W-30.

[DrewNJ]

Nothing wrong with a 15w at all, and if you have a vtwin it's the original weight spec'd for the same motor used in the Aprilia bikes.
BRP specs that oil because it is used on a lot of their other platforms, and it works well.

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[garb55]

Can anyone say why so low a viscosity ( 5w) when most of these machines are ridden in plus thirty weather ? I doubt if the oil ever gets down to be as thin as 5w. Since it is obvious that it needs a 40 wt. for hot running, whats wrong with a 15w40 oil ??

I ride even when the weather is at 0 degrees
heated clothes work great

[MS_Spyderman]

After all, these machines are made in Canada.

[Bob Denman]

I would guess that a thinner oil would probably give better fuel economy... :dontknow:

[JayBros]

I would guess that a thinner oil would probably give better fuel economy... :dontknow:

It's actually more complicated than that and also includes additives that reduce friction to improve fuel economy but are not friction modifiers such as molybdenum disulfide. There also are thickeners added to retain the desired viscosity in a multi-viscosity oil when engine temperature and operating rpm are increased. But I'm not an engineer so I am not qualified to discuss in greater detail with any authority.

[Bob Denman]

:D Are you sure that you didn't stay at a Holiday Inn express last night? :thumbup:

[JayBros]

No, but it might have been a Snickers I got into.

[Bob Denman]

:thumbup:

[Dan McNally]

I'm not an engineer or a chemist, either - but as I understand it, a 5W40 oil is a 40W oil at 100 degrees Celsius, but performs like a 5W oil when cold, so a cold engine cranks, easier. When I was stationed at Plattsburgh AFB, NY a 5W oil sure would have come in handy when starting my car at -15 F. Even with a good battery, it would only turn three or four times, and if it didn't start, immediately, you weren't driving anywhere!

This site explains it well: http://www.upmpg.com/tech_articles/motoroil_viscosity/

[Highwayman2013]

Can anyone say why so low a viscosity ( 5w) when most of these machines are ridden in plus thirty weather ? I doubt if the oil ever gets down to be as thin as 5w. Since it is obvious that it needs a 40 wt. for hot running, whats wrong with a 15w40 oil ??

Please read:http://www.bobistheoilguy.com/

[MikeT]

5W-40 just gives easier starting in cooler weather. If you notice some cage oils are now 0W-30.
It's just not cage oils. The XPS Full Synthetic is 0W-40.