Synthetic Oil vs. Semi-Synthetic

I've been using a synthetic oil (Mobile 1) in my 450 since new and always had a clutch growl when I start out in first gear at the beginning of the ride and also if I started in second gear later after it was warmed up. It sounds like it's slipping. I just put in a semi-synthetic oil and not one growl all day long?? Has anyone tried both types of oil, if so what were your results?


I use Mobil "S" in my 426 only for the fact that it costs too much for Mobil 1 if you change it every ride, i tore it down at 6000 ks to have a look and the motor was as sweet as :):D

My 2 bucks, (Aus)

I hope you were running Mobil 1 synthetic motorcycle oil and not automotive. Mobil no longer recommends Mobil 1 synthetic automotive oil in motorcycles. They changed the formulation recently and warn against clutch failure. I personally recommend Maxima Ultra or Extra synthetic oil. But at least us a semi or full synthetic motorcycle specific oil without moly.

Synthetics do hold up better under heat. I recommend a true synthetic ESTER lube vs the ultra refined petroleum PAO lube.



What specific M1 were you running? As long as the little circle label on the bottle does NOT say "Energy Conserving" or some such thing, it does not have the friction modifiers that most auto oils contain. The friction modifiers will speed up clutch problems/failures.

I'm running a semi-syn Belray oil in my 450E and the clutch is very quiet. I ran the same oil in my 01 400E and the clutch was usually growly until the engine warmed up.

My intent here was not to start the great debate over Oil brand or type. I believe that has been discussed to some length and everybody has their own opinion and preference. I was just interested if anyone else has changed from a Synthetic to a Semi Synthetic and noticed less clutch slipping.

The Mobile One I used was the 15/50 red cap, and the Semi was a brand without the friction modifiers.


i subscribe to motorcycle consumer news and this month's issue has the final results of the oil tests..very interesting. bottom line is just change it often and as far as the mc oil vs the auto oil...not much difference at all. go figure

Sounds logical to me :):D

Motorcycle Consumer news is trash. I have read their articles and shown it to Motorcycle oil experts and the conclusion is that they are misleading the public. I have recently been told that Castrol would soon be putting a warning label on GTX to not use in a motorcycle. I have posted several articles on TT and look them up and read. If you want to chance damage to your engine and clutch go ahead and use automotive oil. I know your dealer will be glad to sell you parts . Your choice, parts or Oil.


Dwight :)

Well here is another "informed" site on the subject of Synthetic oil, they seem to know what they are talking about.

Myself I have used Mobile One 15/50 for two year now. A year and a half in my 520 and six months in my 450 without any problems at all. Recently I tried a Synthetic Blend and it stopped some of the growl when starting in 2nd gear or first thing in the morning. From everything I have read Synthetic just protect your engine better then Non Synthetics. Since I am no expert and have no way to test them, all I can do is read what other Experts have said about the subject then make my own decision. I think everyone will have to do the same. I am not trying to convince anybody one way or the other just passing on info. For me I will always use a Synthetic oil or Blend in my bike, and my truck.


well said lee.

dwight, i totally respect your opinion and value the information that you bring forward. but, for myself, hard facts over rule what any so called professional may state. there are way too many people that have been running the red-cap for years in the same bike. on top of that, i have not heard of one single case were mobil-one was the cause of engine or cluth failure for that matter. i ran the red-cap for an entire year in my 520 and never had a single problem but clutch noise (big deal). i'd still be running it in my 450 if were not for my Motorex sponsorship. and still, i'm running their full synthetic, not the semi. like lee said, do your own research and make your own decisions. the folks at mobil one make their recomendations based on liability and marketing, as far as i'm concerned. yes, motorcycle specific oils may have better additive packages, but that does not mean that the red-cap will not do a good enough job. 90% of poeple that i know that ride 4stk's use the red-cap and a couple of them have had the same bike for mulitiple years. i've said enough.


My two cents:

I run the red cap Mobil1 15W50 in all my thumpers, no problems, no need to change now. This has been my routine for the last 4 years. I am open to new things, but this is the best bang for the buck IMO. Good day.

Let me also add, 6000ks and i fan the crapper out of my clutch and there was hardly any wear, i recon some manufacturers say use mc oil only because ............ oh yeah, it effects there pockets. :):D

Keep running the Mobil 1 automotive stuff. They themselves have recently said not to run this oil because of a recent formulation change. But that is only their opinion. I wonder why Mobil one now makes a Motorcycle specific oil ?


So Mobile can charge twice as much for the oil??

It's kind of funny that two years ago Mobile had no problem with using the 15/50 auto oil in motorcycles. Now that they have a motorcycle specific oil the 15/50 "Auto" oil is bad for your bike?? :)


They changed the oil due to goverment requirements. THEY CHANGED THE FORMULATION !

What government requirements forced them to change it? It still does not say "Energy Conserving" on the back, right?

You don't see "Energy Concerving " on anything but the low viscocity oils. The thinner oils allow the engine to turn easier. But they have to add even more of the friction modifiers to lube the engine properly. Automotive oils are still low on Zinc and Phosphous additives due to the catalatic converters. Use if you must a Diesel type oil. These oils have more pressure additives like zinc and phosphous and no friction modifiers. But these oils like automotive oils are designed for low rpm engines with large bearings. The oils don't have to put energy conserving on them. Also the goverment regulations are aimed at the Auto industry and they dictate to the oil industry what special oils they have to have to meet the government regs. We have been through this seveal times and like I said use what you want But don't tell everyone that the oils are the same. But when someone asks a question about a possible oil related problem the answer isn't to defend the culprit. I have said what I use but I also have said to use a good high quality motorcycle specific oil. ( except Honda HP4M , it has friction modifiers. ?????????). KTM recommends a high quality motorcycle synthetic. Because of the heat and rpm and wet clutch.

I guess the same guys who use cheap automotive oils also use Chen Shin Tires because rubber is rubber.

I am tired of the oil argument. Facts are still Facts even if you choose to ignore them. If you can get by with cheaper oils then go for it. But what about the one time you need the extra protection or your clutch goes out prematurely ? If you like Mobil 1 so much , use their motorcycle oil. You can probably still get that at Wal-Mart also. Even Castrol oils have long had Motorcycle specific oils as does SHELL. But Castrol USA didn't think the motorycycle market large enough so they quite making and importing to the USA. But now they are back again trying to sell Motorcycle oils. But they too have having trouble with the oil is oil mentality . I just in past 2 weeks heard that Castrol GTX would be coming out with a "not for Motorcycle label ". This came from a Castol oil company rep. SHELL has never to my knowlege sold Motorcycle oils in the USA. ( EXCEPT, private labeled SUZUKI CCI, this was sold in Europe 20 years ago as Shell Super M ).



Lee, You had a problem that seemed to be cured with a change of oil brands. What was the Semi-Synthetic that you used ? Golden Spectro ? Just wondering.

I'm tired of the oil debate, too. But you stated that some govt rules forced the changes in Mobil 1's formulation. Please be specific about what rule that was.

Check out this thread about reading oil lables from Chevron's site. Seems "Energy Conserving" oils are the ones with friction modifiers.

From what I've read Exxon did not change to a SuperSyn additive due to government regulations. It was to allow Mobile 1 to pass a much wider battery of industry oil standards. The ingredients of this additive is still secret so who knows if it's better or worse for your motorcycle.

As far as motorcycle specific oils yes they do add more Zinc and Phosphorous then auto oils. The zinc in your oil comes into play only when there is actual metal-to-metal contact within your engine, which should never occur under normal operating conditions.

I believe the main thing about any oil is how long you keep it in your motorcycle and how you ride it. In my Harley I use a motorcycle specific oil because I change it every 5000 miles. The oil I use in my KTM is change every 150 to 200 miles. Under those conditions I do not think it matters which oil I use as long as it does not have the Energy Conserving label. I use the Synthetic oil because it handles heat better and leaves very little residue in your engine and clutch. If I was racing all the time in extreme conditions, (hot and high rpm's) then I would use a motorcycle specific synthetic oil to give me the added protection.

To answer your other question yes I changed from a Synthetic to a Semi to see if it would help in the clutch growl first thing in the morning. The first ride was better but by the second ride it was back. I am now going back to the full Synthetic Oil (15/50 Mobile 1).


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