The Definitive Oil Thread.

[NixR6]

ok answer me this: I am running 15-50 mobil 1 in my bike and everytime i buy it my dad tells me its not good for the bike. I mean, his argument is sound...basically that the higher viscosity oil is tougher for the bike to circulate and it wont lubricate as well in this respect, especially when the bike isnt fully warmed up. The oil never gets hot enough where the reccomended oil wont do its job...and if our bikes needed a heavier oil yamaha would have told us...

Since our bikes dont have oil temp guages i was wondering what kind of temps we are dealing with because the more i think about it the less i can justify the 15-50 i am running

[Thrak]

I'm not sure what you're asking... are you asking if the oil ever gets up to temp? Are you asking why you use it? Are you asking why use 15/50? Just look at the price of the oils that are "motospecific" and you'll be able to justify it really quick. In my race bikes I use 5w30, but it has friction modifiers that scare everyone that doesnt use it... I've never ever had a problem in 3+ bikes for thousands of miles *shrug*

The only thing I would agree w/ him on is that you should let the bike warm up before you romp on it, but you should be regardless of the oil you use anyway. What background does your dad have?

[NixR6]

My dad has been riding since he was a kid....and thinks that his previous truck engine died quickly because of using the wrong oil. I generally trust him because hes an engineer and stuff...but he can also be stubborn as well. I mean, i am a senior at Umass for engineering and i know that if an oil is too viscous that it wont pump through the engine properly...we had this problem in lab.

What i was questioning were the typical oil temps of the 6 to try and determine how much thicker the 15-50 is at operating temp and if it is indeed too thick or not. I use it mainly because i cant find a good synthetic 10-40 without friction modifiers and i dont wanna waste $$ on motorcycle specific oil.

[Rob Sherman]

i cant find a good synthetic 10-40 without friction modifiers

I've got some Shell Rotella T 5w40 (no modifiers)that I am going to use in the next week or so.

$14 for a 5qt. bottle, can't beat that. I've heard good things about it. So I am going to give it a shot. I do wish they would've had it in 10w40 though.

[thwwx]

Originally Posted by NixR6

My dad has been riding since he was a kid....and thinks that his previous truck engine died quickly because of using the wrong oil. I generally trust him because hes an engineer and stuff...but he can also be stubborn as well. I mean, i am a senior at Umass for engineering and i know that if an oil is too viscous that it wont pump through the engine properly...we had this problem in lab.

What i was questioning were the typical oil temps of the 6 to try and determine how much thicker the 15-50 is at operating temp and if it is indeed too thick or not. I use it mainly because i cant find a good synthetic 10-40 without friction modifiers and i dont wanna waste $$ on motorcycle specific oil.

50 SAE is specced by Yamaha in the user manual that comes with the bike as long as your ambient is sufficiently warm, you're worrying too much.

If u want a non-motocycle specific 40 oil without friction modifiers, with plenty of antiwear and acid neutralising additives, try Mobil Delvac 1 5w40. I've tried quite a few oils most of them bike specific, this is among the few that I like and actually continue to perform well past 2k miles. Yes, it is a diesel oil like the rotalla, but it is 100% suitable for wet clutch and petrol engines, don't let marketing confused you into paying more money for a similar or lesser product.

[Thrak]

well, the oil is a 50wt at temp, instead of a 40wt.

Instead of Delvac1, you might have an easier time finding Mobil1 "Truck and SUV" oil, which is the exact same as Delvac1 in a different container. Still 5w40.

I think you're worrying too much...

If your dad was using something even close to what the manual reccomends, I think you can rule out oil for killing his engine... what happened to his engine btw? Spun bearing? Piston seizure?

[03quickr6]

Is there a issue with mixing non synthetic and synthetic oil? I have (2) quarts of Mobil 1 as well as various quarts of different type/brands of non syth. I could easily just go grab another quart or two but if I have these I am curious if I should not mix them.

[NixR6]

You should have no problem mixing a modern synthetic with dinosaur oil...they are completely compatible. If its an older synthetic i wouldnt...the older ones arent compatible (as in when synthetic first came out). I was just going over various oil threads and i am switching to a 5w-40...the 15-50 is just way to thick for where i live (MA)...when i start the bike up when its in the 40's the engine is seeing a VERY viscous oil and that cant be good...although once warmed up its fine its still not good on start-up. Plus 5w40 is plenty thick enough for the 6...i guess i kinda answered my own question!

[Thrak]

Ah.. Nix, if I had known you were in such a cold climate, I would've said 15w50 might be too thick... sorry I didnt even notice it. Get the "Truck and suv" Mobil1.. its friction modifier free so you should enjoy it.

[Oh3AreSicks]

Awesome thread!!
But it's not really definitive until Jumperalex stops by...