MOBIL 1 in your bike..? safe for clutch?

29 replies to this topic
  • joecallan

Posted April 06, 2001 - 03:45 PM


I would like to use synthetic oil in my bike. I know it's excellent for engine wear and preventing break down at high temps..

Does anyone know if Mobil 1 would be too slippery on the clutch?

What wt.?

  • Jemtec

Posted April 06, 2001 - 10:48 PM


Mobil 1 makes a Motorcycle formula I understand. And any synthetic is wonderful. But, Not the Standard Car Synthetic. It has a friction modifier that makes surfaces more slippery. In the case of most motorcycles, the Clutch is submerged in oil. The Plates contained in the clutch are friction based. They "grip" one another and lock the piston power to the transmission. :) But, with the slippery formula, they have more trouble gripping, and cause slippage. This isnt a good thing.
The manual recommends a non-friction modified formula and 10/30W is the most used. You can use anything from anyone..but try and get a good synthetic. I cant seem to find anyone other than Yamaha over here that has a Synthetic for less than 8.00 a Quart.. YIKES.. I only have hit 100 miles on My 01 Wr 426 and I will be looking for something else other than Yamalube 4(nothing wrong with it but I want a synthetic oil myself) in the next 200 miles when she hits 300 for her next oil change.
Good luck.

[This message has been edited by Jemtec (edited 04-07-2001).]

  • MN_Kevin

Posted April 07, 2001 - 12:52 AM


A lot of WR owner are using Mobil 1 with ZERO clutch problems. There are several posts on this subject already. An article was posted by a Chemical engineer out of CA that was tired of paying big bucks for "Motorcycle" oil and performed his own tests.

Mobil 1 performed best, and regular old Castrol GTX outperformed Spectro motorcycle oil. Don't get caught up in the "shearing strength" of bike oil. It is just a bunch of garbage lies the manufacturer uses to scare you into $6/qt oil!

I DO use Mobil 1.

  • Russ_P

Posted April 07, 2001 - 06:35 AM


Mobile 1 15w50 in my bike. Check those old posts, just use mobile 1 as your search topic.


  • joecallan

Posted April 07, 2001 - 04:31 PM


grrrrreat! thanks guys.. i'm changing my oil to Mobil 1 15/50 soon!

funny thing is that my grandparents were Mobil oil distributors for over 45 years and I used to stack cases of Mobil oil everyday in high school. We've always used Mobil 1 15/50 in our cars. Daddy would be proud. :)

  • Clark_Mason

Posted April 07, 2001 - 06:23 PM


Your dady should be proud as Modil 1 is one great product and is a tough act for any oil anywhere to follow. Use Mobil 1 15w50 and be happy. Enjoy the savings over Yamalube and similar products.



  • Ward

Posted April 07, 2001 - 11:17 PM


I want to make sure I have this right. The Mobil 1 15/50 is automobile oil, or is it their Motorcycle formula?
I’d love to get away from the $7.76 a quart I pay my local dealer here in Alaska.

Alaskan rider
'00 WR400FM
WR timing
air box lid removed
Throttle stop trimmed
MSR skid plate
Works frame guards
Baffle removed
'00 Grizzly YFM600

  • MN_Kevin

Posted April 08, 2001 - 02:37 AM


Automobile Oil!

  • Jemtec

Posted April 08, 2001 - 12:26 PM


I appreciate the thought about using a good "synthetic" oil, Such as Mobil 1's 15/50. Its a fine Synthetic.
Ive heard about all this "shear strength" for as many years as I can remember. It does make sense about the clutches misbehaving in the "friction modified" oil that is designed to be a more slippery and more fuel efficient oil for all but a motorcycle engine.
Sounds like some of you are using standard oils, and good car synthetics.
95% of the engine can still utilize these oils fine. It makes total sense in the way that they still protect the engine components. However, it is then also combined with the gearbox. And THAT I feel is creating the confusion.
Id run a standard oil if I could, and in addition, I havent heard of anyone thats really "trashed the clutch" so to speak using a car oil (or knew it was bad more importantly since it wears slowly).Since, most bikes dont "show" the problem in the way a Car or truck would further adds to the confusion (its a wet clutch instead of a Dry). But, Using a bit of science.. A Slippery formula modified oil..or friction modified oil (this uses a special polymer) would obviously cause a bit of clutch slippage. Its just the way it is due to the fact that the clutch plates are submerged in an oil and are also dealing with extremes FAR worse than in a auto engine. More heat, fairly "ineffiecient" carburetion that causes more oil contamination with incompletely burned fuel getting into the chemical additive mix which deplete the cleaning additives and of course oxidation of the oil caused by the wearing factors of a hard working engine AND transmissional "shear" that all gearboxes experience. that would eventually cause some unusual wear in "critical" areas as opposed to a auto Engine which doesnt experience anything near what a Motorcycle can dish out. Even with a "Good Synthetic or base engine oil.
The oil filter helps with Particulate contamination, but that doesnt stop the "chemical side" of things and an effect on clutch operation in particular as all the motorcycle companies claim.
I cant ignore the "cost" variable, and as mentioned, some of you are using standard automotive oil and dont "appear" to be having trouble.. But thats the problem!
What Id like to see the Hard facts from a Lab. Its possible to have the oil analyzed and look for the accelerated Wear in the clutch in particular, comparing both "Motorcycle, non-friction formula oils to automotive oils and Synthetics (they would have to be done separately since synthetics are superior to standard oils). In addition, done by a viable lab.
Until proven otherwise, Ill go with the Motorcycle manufactures as much as it pains me in the wallet. (yes, I would like to pay less money :) )
But, I kinda doubt that ALL the motorcycle companies would be saying "use this oil".. and not have a valid reason for it.
They do have laws against Unsubstanciated and unproven claims. Like what happened to Slick 50 and the teflon based oil they produce.
Im not sure that they would want to "lie" and be caught with thier pants down. Especially when they all desire your business for thier machines.
I do appreciate that one of you mentioned you had known a chemical engineer that was tired of buying more expensive oils, and not liking it. How long ago was the study?. Did he test all variables?.. Did he test ALL oils?.. Was the test done in various motorcycles with similar results?
I dont want to sound picky, but I spent 6500.00 on a Motorcycle, and I dont want to "assume". The Wr 426 is a Performance work of art, and I KNOW its beating the crap out of its oil. Just the nature of the Monster and I love it!.
I dont want to sound Anal about it either, but I also want cold hard data. And Im sure everyone else would as well. Tens of thousands of riders. :D
Who knows.. maybe someone isnt telling the truth?..And maybe we have been misled?

  • Hick

Posted April 08, 2001 - 03:19 PM



I don't think you're anal, and you made a good point about mfg. claims.

Oils with friction modifiers are labeled as such. Look for a circle with the letters "EC" in it (denotes that "energy conserving" friction modifiers have been added).

I don't know why, but all 15w-50 synthetic car oils I looked at down at Pep Boys (only like 5 brands) didn't have friction modifiers, other weights did, even Mobil 1, so check the label before you put it in your bike.

Mobil 1 15w-50 will not cook your clutch, and since we are overcharged for every other damn thing why not use it?

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  • Jemtec

Posted April 08, 2001 - 09:44 PM


I didnt know that the Mobil 15w50 didnt have the modifiers. Since it doesnt, Its safe to use Im sure :) Certainly better than Standard oil, or "Energy conserving".
I take your word on this one.
Thanks hick.

  • Ynahg

Posted April 10, 2001 - 03:02 AM


Originally posted by Jemtec:
I didnt know that the Mobil 15w50 didnt have the modifiers. Since it doesnt, Its safe to use Im sure :) Certainly better than Standard oil, or "Energy conserving".
I take your word on this one.
Thanks hick.

For 1 year I have been riding with 100% synthetic Marly Black Gold Bio-Carat oil.
Just in case Marly Balck Gold oil contains colloïdal graphite, a dry lubricant with excellent anti-wear properties (prevents metal to metal contact !!!!gear box, camshafts end cylinder!!!).
Since i did not notice ANY clutch problems, lots of friends of mine (VRF, CBR900RR, YZ426 '00, XR600 ...)did the same, with excellent results. check out

'99 WR400 F, YZ exhaust, throttle stop trimmed, WR timing, airbox cover removed

  • jetguy

Posted April 11, 2001 - 12:01 PM


Of course this is obiviosly info that's coming from a grape on the vine of utter heresey but, from what I understand any API rated oil after "SH" uses some sort of friction modifier. Around this time Zinc and other toxic additives that prevented wear on metal to metal contact (after your oil wedge has disappeared for one reason or another) were removed or substatially reduced in the additive package to reduce emmissions.

So, I use a motorcycle specific oil. I used auto oil "SJ" once in my ZX9R and it dramatically changed the feel of the clutch so I switched back. I wouldn't say it was damaging the clutch but the progressive feel was lost.

I am not sold on synthetics for motorcycle use. They are just way, way, I mean way too expensive. Full synthetic here in Canada can exceed $15 per Liter (Quart). Industrial ester based sythetics used to protect multi-million dollar gas turbine engines are half that price. So, I can't see the value!!! That engine in your WR is gonna need a rebuild one day, IMHO you can't really delay that with a synthetic oil change.


2000 WR400F
2000 CBR929RR
Our Friend and Ally: Gyroscopic Precession

  • Ynahg

Posted April 11, 2001 - 10:29 PM



I may agree about a different feeling in the clutch, but once you're used it doesn't seem to be a problem.

For more info check out :

'99 WR400 F, YZ exhaust, throttle stop trimmed, WR timing, airbox cover removed

  • KickInTex

Posted March 26, 2008 - 08:56 PM


I have been using the Mobil 1 Motorcycle Oil 20W50 in both of my WR's for years with no problems. It's available at Autozone for about the same price as regular Mobile 1. They carry it in both 10W40 and 20W50:ride:

  • pcmech2

Posted March 26, 2008 - 10:10 PM


sir, i agree with your post, BUT you responded to a 7 year old post. i am a newbie and only have like 12 posts and did the same thing to @ least 3/4 of them, so i agree the post is relavant to us. that being the case.... have you ever tried atf dexron II in your bikes??? anyone, diffenerences, consequences... lets see if we can get this thread going...

  • mvryder

Posted March 27, 2008 - 07:46 AM


I have a wr450 and an xr250 and I looked at the manuals (which spells out which oil not to use). I went to the auto parts store and found the most expensive oil that meet both criteria and had the widest range. Castrol semi-synthetic 10-40. ALL the full synthetics i found had energy conserving or energy conserving 2. The manuals said don't use I don't. Honda says no energy conserving and the Yamaha book says no energy conserving 2...i just look for a label with neither. So I have an oil I can buy almost anywhere (wallmart, target, autozone) and it is 3 bucks a quart. Just read the manual it spells it out for you.

  • Island Boy

Posted March 27, 2008 - 08:23 AM


I use mobil 1 racing 4T (10W-40) fully synthetic motorcycle oil. There is no clutch slip and gears definitely shift smoother. I love the stuff. My buddy switched to mobil 1 4T in his XR650R and has had the same great results. Apparently the 650R was notorious for clutch slippage when using synthetic. No problem at all with the Mobil 1.

  • Wiz636

Posted March 27, 2008 - 09:37 AM


have you ever tried atf dexron II in your bikes??? anyone, diffenerences, consequences... lets see if we can get this thread going...

Do not use ATF in your thumper! :prof: The oil in the WR/YZF lubricates the motor as well as the tranny so you have to use a motor oil rated for wet clutch use.

Guys have run ATF in 2 stroke tranny's with decent results however.

  • Wiz636

Posted March 27, 2008 - 09:45 AM


ALL the full synthetics i found had energy conserving or energy conserving 2. The manuals said don't use I don't. Honda says no energy conserving and the Yamaha book says no energy conserving 2...

Most full synthetic oils designed for automobile use have energy conserving additives to make the oil more slick and the problem with that is that it is so slippery that the wet clutch in motorcycles will not lock up properly. Like mvryder says stay away from those.

A motorcycle-specific synthetic oil will be rated for use with a wet clutch. Mobile 1 MX4T and Amsoil MCF are two excellent motorcycle-specific full syn oils that hold up well in a transmission. The gears in the tranny are signficantly harder on an oil than the engine is and can cause an oil to shear out of viscosity in a matter of just a few hours of hard use. Both the Mobile 1 MX4T and the Amsoil MCF have proven to be very shear resistant.


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