Does anyone run valvoline 10w40 atv oil in their yz450f?

So i haven't started it yet with that atv valvoline yet, should i look for something different?

Rotella 15/40... Close thread...

So i haven't started it yet with that atv valvoline yet, should i look for something different?


No, I mean, I wouldn't drain it out unused, or anything.  It's probably alright, at least if changed often, and may actually be excellent.  But unless you know for sure, either have a used sample tested, or just change it often,


Blackstone Labs:

I recall reading on a thread recently that someone called them to submit a sample and they were told it needed to have 50 hours of run time on it. I haven't inquired myself, just read it here.

Gray, thanks a lot for taking the time with these threads; I learn a ton.

You can have them test new oil if you want.  I never had them give me any grief over how old the sample was. 


Remember that the bulk of their work is with fleet vehicles, and UOA's in that world are most often used to keep an eye on engine wear and condition by evaluating the metals contained in the sample.  Low mileage samples aren't very useful for that purpose, but any oil sample can be tested for viscosity.  We just aren't testing for what they normally look for.


In our particular application, shear stability is the usual first point of oil degradation by a considerable margin in almost all cases.  After that, it goes to heat tolerance and tolerance for chemical contamination.  Very rarely would a bike like the YZ450 have an oil fail for any reason other than viscosity loss.  If they find actual dirt in the oil, it's good to know that, too, so you can try to figure out how it got there and stop it.

When i used to work in a parts house, i had a customer who specifically bought that atv oil for his 4x4 quad. Said it was good for that type of transmission.

Personally, Ive never tried it since the bike doesnt take that much oil i want the highest quality lube i can get. That atv oil is only a synblend IIRC.

I have tried mobil 1 4t. I found that my bike runs noisier with the mobil 1 and its black within 4 hrs.

been running castrol 4t 10w50 on recommendation from a buddy who used to be a bike tech. Ive had excellent results. Oil stays clean longer and engine is quieter. I still change at 6 hrs no matter what. The thought of clutch particulates circulating through my engine is scary. The oil usually starts smelling of fuel at this point as well.

Havent tried a diesel dino 15w40. I bet it would combat fuel dilution and breakdown by shearing well. With a car engine you can go lower on the viscosity with the first number but you should never go higher with the first number than the manufacturer recommends to avoid dry starts. Not sure if this applies to a 4 stroke 450 it does have an oil pump so i dont care to find out.

I really believe that mobil 1 quality has dropped in recent years. I stopped using it in my cars. They seem to be noisy with this oil. I might try motul or amsoil in the future ive heard good things about them as well.

Edited by NW Briff

Does the first number matter as much? I like to run T6 (JASO) 5w-40 synthetic. Is a 15w-40 non synthetic better? People talk about startup and high temps. I believe 5w can go up to 120 degrees, which I would never get to.

I have a rekluse z start i wonder if that matters

Rekluse suggests using Rotella T by name.

I don't have a Rekluse, I'm just wondering about the first #

So with my rekluse i should use rotella?

Yes, but you don't have to.



I wonder if my mobil delvac would work that's what i use in my dodge witn a cummins 15w40. Then i wouldn't have to have both brands in my garage

Regardless of what Rekluse says, I have never run Rotella, and won't be using it.  Both the Amsoil MCF I used to use and the Mobil1 Racing 4T I currently use work perfectly with the clutch as it is.


Regarding the meaning of the first number in multi-grade oils, the first number is the "winter" weight (thus the "w"), or the equivalent SAE engine oil viscosity at 70 ℉.  The second number is the equivalent SAE viscosity at 200 ℉, or the normal operating temperature range.  This means that the oil will behave as a 5 or 10 or whatever weight when cold, but will resist thinning with heat so much that it is still as viscous as a 40 weight when hot.  


It also means that the basic oil that the blend started out with was a 5 or 10 or 15 weight that had specialized long-chain polymers added to it to prevent the thermal thinning.  These are bulky molecules, and are what the transmission destroys if they aren't tough enough for that service.  When that happens, the full temp viscosity indicated by the second number falls off sharply. 


5 weight oil will not service a YZ450 to anywhere near 120 ℉.  A 30 weight is only acceptable up to 70 ℉.  A 5w-40, remember, is not a 5 weight at operating temps, it's a 40, and a 5, 10, or 20w-40 will serve up to the same 115-120 ℉.  The difference is in the minimum temperature at which they can be used.  

I just spoke to a Rekluse engineer last week and he recommended any high grade motorcycle oil that is meant for wet clutches and meets the JASO-MA/MA2 standard. I asked him about Shell Rotella and he said you can use it if you want to run cheap oil.


I use Mobil1 Racing 4T 10w-40 in my 2009 yz450f (w/z-start pro) and everything works perfect, FWIW.

Edited by blueberg17

I want to run cheap oil, and lots of it, often.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now