Synthetic oil

3 replies to this topic
  • xl-one

Posted October 17, 2008 - 08:28 AM


Hey Gang
Is full synthetic oil ok in my 04 yz450 or should I stay with conventional?
Any ideas on brands and weights? I assume the engine and trans share the same oil as in the old days

  • Wiz636

Posted October 17, 2008 - 08:44 AM


Welcome to TT. Familiarize yourself with the search function as there are several threads regarding your exact question.

To answer your question though, synthetics are an excellent choice but you do not want to use any oils (synthetic or otherwise) that contain friction modifiers as they can cause the clutch to slip.

The two oils that I will use in my bike are Amsoil MCF and Mobile 1 Racing 4T. Both are excellent oils that are specifically engineered for use with wet clutches.

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  • grayracer513

Posted October 17, 2008 - 11:00 AM


The two oils that I will use in my bike are Amsoil MCF and Mobile 1 Racing 4T. Both are excellent oils that are specifically engineered for use with wet clutches.

Two excellent choices. The worry over using synthetic oils in clutches is based largely on very old information (older even than me) and myth. The main difference between the two is that conventional oils are the product of refining, which is the process of removing the stuff they don't want, whereas synthetics are the product of combining only the pure base components you want in the first place. Instead of trying to filter out the garbage, it is simply never included to start with.

Synthetics are not slipperier than petroleum oils unless things are added to them, nor, in the simplest sense, do they even lube better. They are more durable, stable, and hold up better under extremes of stress, or at least, they can be. The clutch concerns come from the fact that very low friction oils bearing the words, "Energy Conserving", or "Reduces Friction", and that also carry "API ECII" on the label MIGHT cause problems. The fact is that virtually all of those oils are synthetics, but not all synthetics are EC II.



  • aggiemoto99

Posted October 17, 2008 - 11:05 AM


Excellent post gray...

Many synthetics "lubricate better" not because the oil does, but as gray said the additives they use are better.

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