Engine oil weight question for HD V-ROD engine

[Markk9]

Question about oil used a Harley-Davidson V-Rod engine, it's a single sump set up. H-D book calls for 20-50 unless temp is below 40, the 10-40.

Why is 10-40 only ok when the starting temp is below 40? I understand the 10 weight oil flows better at lower temps, but with synthetic does it matter? How much better does a 10 weight synthetic oil flow compared to 20 weight synthetic? Once the engine is warmed up to operating temp and running on the highway, does 10-40 offer less protection then a 20-50? I would like to know, I'm a 365 rider, as long as there is no snow or ice on the road I ride to work. Winter time morning temps can be down in the upper teens and low 20's.

On my non H-D bikes I run a motor cycle rated synthetic oil 5w-40. Would this oil cause problems to a V-Rod's engine if used during the summer?

 

[Indydriver]

There's a reason the manufacturer recommends what they recommend. You can do whatever you want but, if it were me, I'd do what their engineers tell you is best for the motor. "Flow" is no different from syn to conventional.

 

[oggb]

I'd use 20w-50. That's thick oil and Harley must be recommending it for some reason. I'd expect a 10w to have significantly better cold flow than a 20w.

 

[229]

If you are riding that HOG enough to change the oil twice a year then run both at the correct season. You already know about wet-clutch oil. A V-Twin 20W50 will provide the most protection when you kick it in the hind quarters. Good fortune.

 

[Robenstein]

Castrol makes a synthetic 10w50, as do others. Get the best of both worlds.

 

[kballowe]

Yeah you wouldn't think that they'd spec a 50 weight for a water-cooled bike. Does Harley even offer a Genuine Harley 40 weight motor oil?

On the flip side - there are many Gold Wing owners that use a 50 weight in their bikes. I know of a couple that have in excess of 200,000 miles on them running 50 weight oil. Mind you, the owner's manual specs a 10W-30.

Not myself being a Harley Engineer, my first inclination would be to follow the recommendation in the owner's manual. It'll probably work out just fine.

 

[RC46_Rider]

I would stick with what H-D recommends. There IS a reason they
recommend the 10W-40 in cold weather. Probably there are two reasons: (1.) Better cold starting...easier on the starter and battery and quicker oil flow. (2.) That is an AIR cooled motor.
If you are riding in sub-freezing weather, I would bet a LOT of money that engine runs very cool; probably below optimum operating temp, which is why a 40 Wt. oil is just fine. It takes "forever" to warm up an air cooled engine in really cold weather. The equivalent would be a liquid cooled engine with the thermostat stuck full open at all times. That engine has enough cooling capacity to deal with cruising two up at 70 mph in 105 F temps in the summer...and that same cooling capacity is still "running full blast" when it is 25 F outdoors. ....again....you can bet every dollar you have that H-D engineers have run all kinds of tests before coming up with those viscosity recommendations. Have you ever felt the side of the cylinders with a bare hand when riding in 25 degree weather? I bet that motor is just "kinda warm" even after a highway ride; it is not going to be "hot" !

Bottomline: in an air cooled engine, the oil viscosity requirements are greatly affected by ambient temperatures because there is no way to regulate or limit cooling system operation; it runs "at maximum cooling" at all times....even when it is 21 degrees outdoors.

 

[BigCahuna]

The subject at hand is a water cooled motor. The only water cooled motor that Harley makes, at the moment.,,

 

[Propflux01]

Try the Middle: 15W-40.

 

[Lost1]

Originally Posted By: RC46_Rider
...That is an AIR cooled motor.

The Revolution engine in the V-Rod is water cooled. You can verify at HD's website.

 

[car54]

Ive found almost everything RC46_Rider says is false. His advice is never on target. go read his previous posts, it is comical.

 

[Clevy]

Originally Posted By: RC46_Rider
I would stick with what H-D recommends. There IS a reason they
recommend the 10W-40 in cold weather. Probably there are two reasons: (1.) Better cold starting...easier on the starter and battery and quicker oil flow. (2.) That is an AIR cooled motor.
If you are riding in sub-freezing weather, I would bet a LOT of money that engine runs very cool; probably below optimum operating temp, which is why a 40 Wt. oil is just fine. It takes "forever" to warm up an air cooled engine in really cold weather. The equivalent would be a liquid cooled engine with the thermostat stuck full open at all times. That engine has enough cooling capacity to deal with cruising two up at 70 mph in 105 F temps in the summer...and that same cooling capacity is still "running full
blast" when it is 25 F outdoors. ....again....you can bet every dollar you have that H-D
engineers have run all kinds of tests before coming up with those viscosity
recommendations. Have you ever felt the side of the cylinders with a bare hand when
riding in 25 degree weather? I bet that motor is just "kinda warm" even after a highway
ride; it is not going to be "hot" !


Well. You lost all credibility when you said air cooled. So even if you are right no one is listening. I suggest instead of putting your foot in your mouth try google. Might help you with these things called facts and how you apply them in a sentence

Bottomline: in an air cooled engine, the oil viscosity requirements are greatly affected by ambient temperatures because there is no way to regulate or limit cooling system operation; it runs "at maximum cooling" at all times....even when it is 21 degrees outdoors.

 

[Ken2]

It has an air-cooled oil cooler, right? The oil temperature will be highly related to air temperature as well as how hard the engine is being run. In addition to the oil cooler, air blowing past the outer surface of the crankcase and sump provide a measure of oil cooling.

If it has a coolant-cooled oil cooler, the oil temperature is much more stable.

 

[BigCahuna]

Originally Posted By: Ken2
It has an air-cooled oil cooler, right? The oil temperature will be highly related to air temperature as well as how hard the engine is being run. In addition to the oil cooler, air blowing past the outer surface of the crankcase and sump provide a measure of oil cooling.

If it has a coolant-cooled oil cooler, the oil temperature is much more stable.
The v-rod is a WATER COOLED motor. It uses air to cool the water. Just like a cars motor does.,,

 

[Markk9]

Sorry RC46_Rider, but I really don't trust any thing H-D has to say about oil. How many years was it that H-D said synthetic oil would damage an H-D motor? Not until they had their own brand did the tune change.

V-Rod is a water cooled bike, also has an oil cooler. But primary cooling is water.