to start using full synthetic oil? Have heard from some to wait until at least 5000km or more.

 

I think thats one of those old myths that wont die. I used full syn in my 6R from 200 miles till about 12K. I just use dino oil now though since i really don't think theres any advantage to using syn IMO.

 

The maintenance record on my bike has the first oil change at 578 miles and the oil used was Castro Syntec 10-40.

Its the only entry on the maintenance record lol but the bike burns no oil at 7K and it seems to run just fine.

 

It's a myth.

Look, the term "synthetic" is no longer a scientifically-based term. It's a marketing term, and it has been ever since Castrol won a lawsuit with Mobil. A Group III hydrocracked petroleum oil can, and is, referred to as a "synthetic". But, it's not...it's just more highly refined than a Group I or II oil.

Also, even if an oil was truly synthetic (man-made, not of a petroleum base), it doesn't mean it's inherently "more slippery", "better", or anything else. Some lab-made synthetics are much worse in performance than refined crude oil.

If you have a mechanic telling you this stuff, he just hasn't kept up with the science of Tribology. Oils are so much better now that they were 20+ years ago, you can't even compare those old oils to today's.

Use ANY modern, non-energy-conserving oil of the correct viscosity, and you'll be fine. Sure, some perform better than others...especially with regard to maintaining viscosity (resisting shear). If you choose a "synthetic", I wouldn't suggest trying to extend the OCI (oil change interval) with a wet-clutch engine that has a carburator. Save yourself hundreds of dollars of UOA (Used Oil Analysis) costs and thousands of hours of studying the subject and take my advice. OR, do the research and the lab testing, and come to your own conclusions.

But, don't take the word of a mechanic regarding oil choices if they do not have extensive knowledge about tribology...I don't care if they build race engines and think everyone that doesn't agree with them is an idiot. Unless they've done controlled studies, subject to peer review, and there are similar repeatable results when others not affilitated with him (her) do the experiments elsewhere, their advice is just anecdotal, and not scientific.

Ask the Porsche and Corvette engineers why they send out their fresh engines with a synthetic in the sump. They've actually done the testing.

Sorry if it comes across as a rant. I just hate the old myths that won't die.

 

Because there are so many types of base oils used and marketed as "synthetic" it's still not bad advise in my opinion since most people don't know what their getting. NOT because it was too slippery, but some synthetic base stocks can glaze the cylinder more than other base oils IF there is blowby past unseated rings, especially on new motors that are broke in too easy. I saw it 1st hand with bores that had somewhat of a plasticized glaze that was hard to remove with a PAO based oil. Yamaha had us use "ring free" ( a techron concentrate) and instruct the owners to go run it hard. If that didn't seat the rings we had to deglaze the bores and install fresh rings. These were RX1 motors that spec'd a high VI (synthetic) oil for extreme cold temps.

As far as slippery, there is some basis to that myth. One attribute of oil is traction coefficient, usually the lower the group base oil the higher the traction coefficient. The diesel industry has documented this due to the trend toward higher group base oils, and it's effect on wear. I'll post a study if I can find it again. In short the use of synthetics that have lower traction coefficient require even more careful selection of additives than mineral oil.

I found it: http://www.valvoline-technology.com/...%20Galling.pdf

 

Nice paper...but, that wasn't about bores. It was about roller bearing followers in heavy duty (Low rpm) diesel engines. While some PAO's may be associated with the pattern you describe, unless you can isolate that PAO as the culprit, it COULD be one of the additives in the particular PAO.

This type of Tribological paper is precisely what I am referring to, when I say the science of oil has progressed rapidly. So, what some "expert mechanic" THINKS he knows...he may not know.

Stay away from Energy Conserving, and run the correct viscosity, and motorcycle engine/transmissions will operate just fine, regardless of whether the oil has a motorcycle designation...or not. In fact, if people want to look into the subject, you'll find MANY motorcycle designated oils that don't hold up as well as MANY non-motorcycle designated oils, when used in a motorcycle!

One of the worst performing oils I have ever used (and I bought it only because it was on a BIG Sale), was a motorcycle designated oil. I think I only ran it maybe 500 miles before I dumped it, because the shifting was soooo poor. Good old Rotella 15w-40 fixed that shifting problem immediately...and that was before it had a Motorcycle designation. But, that was anecdotal only. And, it didn't take into consideration relative starting viscosity compared to Rotella, nor resistance to shear...viscosity and resistance to shear are each very important in motorcycle application performance.

 

Rotella is awesome. Started using that stuff years ago after findint out it was non "energy conserving" thus motorcycle compatible and that my friends father used it in his long haul semi and after he got done with that a became a farmer uses it in all his tractors and combines.

Good stuff, i use it in my 6R, KLX and Jeep.

 

This is why I like this forum (informed and knowledgeable people here)

Ive often heard that oil put in a motorcycle with a wet clutch should have an additive to accommodate the clutch.

On the other hand I hear success stories of using a non-motorcycle oil of the synthetic and non-synthetic type used.

I guess its goes with the old saying that "motor oil is motor oil"

 

A friend of mine bought a Jeep Commander 4 years ago, and it came with synthetic oil. I waited till I had 1000 miles on the bike, but like was mentioned, I think you could use it from day one.

 

Was that directed at me?