10w40 or 20w50

JoeG308 · Jul 19, 2007

I know, I see many different discussions about oil but here is my question. Yamaha recommends 20w40 for the Gen 2 in the owners manual which is pretty much Yamalube. Most of the other brands of Motorcycle specific oil is either 10w40 or 20w50. I know most air cooled bike use 20w50 and most liquid cooled use 10w40.

Of the two weights, which do you use in your FJR?

Two different shops gave me two different answers.

Joe

jestal · Jul 19, 2007

Split the difference and use the Delo/Delvac/Rotella 15W40. Close enough.

The "cold" viscosity is primarily related to cranking speed when the engine is cold so the difference in the "cold" viscosities is much less important than the "hot" viscosity rating. If you have to decide between 10W40 and 20W50 I would choose the 10W40 as the 40 "hot" viscosity rating matches the Yamaha recommended oil specification (20W40) for "hot" oil at 40. The 20W50 would run consistently thicker than the recommended oil when the engine is at operating temperature...which is most all the time....so it would be less desireable than the 10W40. Unless you are trying to start in sub-freezing temperatures regularily the cold oil rating difference between 10W and 20W is pretty much moot.

quicksilver · Jul 19, 2007

During certain warranty work, yamaha paid my dealer to put in 10W40.

It is on the paperwork.

I take this to mean they approve of 10W40.

JoeG308 · Jul 21, 2007

Thanks guys, 10w40 it is. Good explanation Jestal, you made more sense than two different service managers.

Joe

slapnpop · Jul 21, 2007

FYI, 10w40 is call for below ~45 degrees in the early service manuals, and is acceptable in the upper limits of temp as well.

sprint_st · Jul 21, 2007

JoeG308 said:
I know, I see many different discussions about oil but here is my question. Yamaha recommends 20w40 which is pretty much Yamalube. Most of the other brands of Motorcycle specific oil is either 10w40 or 20w50. I know most air cooled bike use 20w50 and most liquid cooled use 10w40.
Of the two weights, which do you use in your FJR?

Two differ shops gave me two different answers.

Joe

Bottom line is use pretty any of the ones you mentioned, IT JUST DOESN'T MATTER.

I use Mobil 1 10w40. I just have a personal preference for synthetics and that doesn't matter either as long as you stick to the maintenance schedule. I would choose a 40 over a 50 but as Jestal will tell you in great detail that doesn't matter either. Warranty is a red haring. I have called Yamaha about this and if you are worried about it, I would recommend you doing it too, but it does NOT void the warranty to not use Yamalube 20w40.

ndivita · Jul 22, 2007

sprint_st said:
JoeG308 said:

I know, I see many different discussions about oil but here is my question. Yamaha recommends 20w40 which is pretty much Yamalube. Most of the other brands of Motorcycle specific oil is either 10w40 or 20w50. I know most air cooled bike use 20w50 and most liquid cooled use 10w40.
Of the two weights, which do you use in your FJR?

Two differ shops gave me two different answers.

Joe

Click to expand...

Bottom line is use pretty any of the ones you mentioned, IT JUST DOESN'T MATTER.

I use Mobil 1 10w40. I just have a personal preference for synthetics and that doesn't matter either as long as you stick to the maintenance schedule. I would choose a 40 over a 50 but as Jestal will tell you in great detail that doesn't matter either. Warranty is a red haring. I have called Yamaha about this and if you are worried about it, I would recommend you doing it too, but it does NOT void the warranty to not use Yamalube 20w40.

Is there any problem in using 10W-30 synthetic motorcycle racing oil?

sprint_st · Jul 22, 2007

ndivita said:
Is there any problem in using 10W-30 synthetic motorcycle racing oil?

This a pure rectal extraction answer, but it probably isn't but I personally would not. Yamaha says to run at 40 and I run at 40. Guess I'm just a lemming.

ndivita · Jul 22, 2007

My understanding has been that synthetic motorcycle oil at 10W-30 was fine as long as it does not have any friction enhancers or is labeled "energy efficient" or some such. This is Lucas 10W-30 racing oil. I will probably change it anyway before my next long ride in October. Just wondered if I am doing any harm by running this stuff in my bike.Lucas Oil

sprint_st · Jul 22, 2007

ndivita said:
My understanding has been that synthetic motorcycle oil at 10W-30 was fine as long as it does not have any friction enhancers or is labeled "energy efficient" or some such. This is Lucas 10W-30 racing oil. I will probably change it anyway before my next long ride in October. Just wondered if I am doing any harm by running this stuff in my bike.Lucas Oil

What you say is correct and like I said, it probably is totally OK. My only concern is that the Yamaha boys preferred something a bit heavier when the engine is hot. If it were only viscosity to consider, the difference really isn't that much. As Jestal will most likely tell you, just because two cans of oil look alike doesn't mean that they are. That Lucas stuff may be way better than any engineer anticipated, who knows. One thing I do know, I wouldn't base my decision on what anyone says on a MC oil thread.

ndivita · Jul 22, 2007

sprint_st said:
ndivita said:

My understanding has been that synthetic motorcycle oil at 10W-30 was fine as long as it does not have any friction enhancers or is labeled "energy efficient" or some such. This is Lucas 10W-30 racing oil. I will probably change it anyway before my next long ride in October. Just wondered if I am doing any harm by running this stuff in my bike.Lucas Oil

Click to expand...

What you say is correct and like I said, it probably is totally OK. My only concern is that the Yamaha boys preferred something a bit heavier when the engine is hot. If it were only viscosity to consider, the difference really isn't that much. As Jestal will most likely tell you, just because two cans of oil look alike doesn't mean that they are. That Lucas stuff may be way better than any engineer anticipated, who knows. One thing I do know, I wouldn't base my decision on what anyone says on a MC oil thread.

Touche'

burninrice · Jul 23, 2007

Do I dare fire up the old motorcycle vs. automotive oil debate again??? I personally use motorcycle oil for the clutches, but I know plenty of people who use regular car oil and haven't had a lick of problems. Any opinions?

sprint_st · Jul 23, 2007

burninrice said:
Do I dare fire up the old motorcycle vs. automotive oil debate again??? I personally use motorcycle oil for the clutches, but I know plenty of people who use regular car oil and haven't had a lick of problems. Any opinions?

That's what ndivita was talking about when he said no friction modifiers. If you go into one of the millions of oil threads on this and other forums your'll get more opinions and explanations than you can shake a stick at. Although there are plenty who will argue the MC only point of view, if you look at the oil container and it doesn't have an ILSAC startburst or says Energy Conserving in the API donut you're OK to use in a bike. What's an ILSAC starburst or API donut? If you are that interested you should do a google search, but they are just labels.

ndivita · Jul 23, 2007

Upon due reflection and information I am going to change out the 10W-30 Lucas Synthetic for 10W-40 Amsoil Synthetic. Something my mom once said about an ounce of prevention.... I know we are all on the edge of our chairs.

10w40 or 20w50

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