Topic: Not wanting to throw another rock through a hornet's nest, but...

[Jonesy]

...this is another oil thread. 

Bear with me and read on. I was in the Honda dealer the other day picking up a few things and I was looking at the selection of oils offered. If you go with the Honda offering, they only offer a conventional/synthetic blend. Since many of us agree on the benefits of full synthetic oil, I asked the counterman if Honda had a full synthetic oil offering. He told me no, and that Honda does not recommend full synthetic oil to be used in any of it's machines, so they do not offer it. 

Granted, we're talking about current production bikes, but this got me to wondering why this is. Any thoughts? I'm really curious.

[SteveD CB500F]

The manual on my VFR800 says to use semi-synthetic as the full sythetic does not work well with the wet clutch.

Now where have we heard that before??

[dusterdude]

just for info,mobil one sells a full syn motorcycle oil.

[SteveD CB500F]

Presumably only for use with dry clutches (like Ducati for example)

[dusterdude]

the mobil one does not have the friction modifiers in it.

[Pinhead]

What about diesel engine oil?

Could you temporarily add ATF to help seal leaky valve seals??

[hymodyne]

I recently changed oil and filter, but used rotella 15W-20 instead of Rotella 5W-20 Diesel synthetic  in my '72 cb500. Man, what a difference! I can't wait until payday, to get some synthetic back in that crankcase...with the 15W, in less than 200 miles, I have consistent oil pressure issues, much more clanking in in the gearcase in low gears and in general, much poorer performance than when I have run the synthetic.

I'm sold on Rotella T !

hym

[dusterdude]

What about diesel engine oil?

Could you temporarily add ATF to help seal leaky valve seals??

pinhead,the atf might cause slippage issues with your clutch.

[Uncle Ernie]

I have found, and have been told by others, that full synth in older machines cause seal problems.  On my older wetclutch bikes, I use the regular Honda oil. For the newer bikes, I use the synthetic blend.  Both are relatively good prices, too, compared to Motul and the like.

[Noel]

I'm using full synthetic in my '73 CB500. Clutch is trouble-free, shifting is much improved, seals are fine. A sample of one, of course, but...

[Chris Schneiter]

And I switched this spring (Two oil threads ago) to "Motorcycle" Synth. Much quieter, better heat resistance, and no leaks.

[Einyodeler]

I`ve said it before and I`ll say it again. Been using Rotella T full synthetic in all of my bikes for years, no clutch slip or oil leaking past seals.
It`s the best oil for the buck in these old bikes.

[Noel]

I've wondered, on occasion, about the seal issues. Ernie says he's had problems and I'm not going to call him a liar. I wonder if it's simply a matter of probabilities: any seal will eventually fail. Perhaps some of those failures simply happened to coincide with a switch to synthetic, thus giving rise to the idea that synthetic equals seal failure?

[Jonesy]

Guys... Guys...

My intent was not to get into the whole conventional/synthetic, moly/non-moly, dealer/store bought, detergent/non-detergent, 3.0/3.7 Quarts, yadda yadda yadda arguments. As I said before I just wondered why if synthetics were so good (and more expensive), why wouldn't Honda  want us using them. Steve's post essentially answered my question. I hadn't thought much about the clutch.

[SteveD CB500F]

Glad to be of service.   

[flyin_]

just for info,mobil one sells a full syn motorcycle oil.

I use the mobile 1 full syn with my 2000 honda magna with a wet clutch and plenty of power with no problems.  I know lots of guys that run the Mobile 1 in their magnas. 

[ElCheapo]

I have never jumped on an oil thread so....


I use Belray in everything. More consistent oil pressures. After all every drop counts. 

[eldar]

Here is probably the primary reason honda does not want synthetic used. IT WORKS BETTER! They would have less coming in the service departments and would make less money on parts! Why do cars these days not last long like they used to? Supposedly they are built better and all this other crap. They should almost never have issues yet they do all the time.

[Roach Carver]

canola/peanut- fifty fifty

[Dave K]

What ever you have faith in a lubricate is what counts, at least to me. I have used nothing but Castrol since the late 60's and have yet to wear out or rebuild a Honda motor, transmission or clutch. I change oil after every ride in the dirtbikes(well weekend) and every 2000 mile or earlier on street bikes( at least once a year). As a matter of fact, I use Castrol in my cars and have not wore them out either. I trade up because the bodies are tired. Personally, I feel the best deal is to make sure you have good oil, changed often. Your mileage may vary.

[nickjtc]

I've missed out on the historical issues on this forum to do with oil. Here is my 44 cents worth (4 cents, + inflation, as usual), plus a question.

In all of my years of motorcycling/driving I have never used anything other than the oils specified in the manual for that particular vehicle. I change oil the oil at more frequent intervals than the manufacturer recommends, because (especially in the car) I do a lot of in town/short journey driving, or in the case of the bike I 'think' I am doing the internals a favour. I always take my used oil to a recycling facility. I've never used synthetic oil, but always use 'name brand' oils (usually Castrol), specific to the vehicle. Never had a problem. Always been happy with engine performance or gas mileage or other issues. Love the price.

So, a question to you folks who swear by synthetic oils. As a complete novice to the use of synthetic oil, what would be the advantage of switching from non-synthetic to synthetic?

Dave K's post snuck in while I was doing this one. Sorry if I am a bit repetitive to his comments!

[Ernie]

i used two quarts of valveline semi sinthetic, before i read these forums,when i first got my bike and my clutch has been slipping ever since. i plan on replacing it this winter if it lasts that long

[number13]

While we are beating this long dead horse...

I just recently switched from regular automobile 30 weight to
Valvoline 10w-40 four stroke oil and noticed two improvements
immediately:
1) Smooter clutch action
2) My shifter seal, which had always leaked even after
    being replaced twice, stopped leaking.

#13

[jbailey]

I use Rotells T Synthetic.  I use it in five bikes ranging from 1973 to 2006.  I have used it for years with NO problems.  It improves shift on every bike. Best Motorcycle oil on the market.

So, a question to you folks who swear by synthetic oils. As a complete novice to the use of synthetic oil, what would be the advantage of switching from non-synthetic to synthetic?

One huge advantage is the lack of polymers which are added to conventional oils to make a multi-viscosity oil.  Polymers shear rapidly in a transmission.  Cars do not share engine oil with the transmission and therefore do not suffer from shear as much.

As to why Honda does not use full synthetic.  It is probably overkill if you follow the recommended oil change intervals.  The shear is why 1500 miles for your motorcycle is reccommended while cars are 7500 or so.  They can sell you conventional oil at the price of synthetic and have you change it more often.  This means more profit for Honda.  It's that simple.

The rumors of seal failure, clutch slippage and such are all urban myths by the way.  Do some research and find out for yourself.

[Noel]

I use synthetic primarily because it makes the semi-grumpy 500 gearbox function better.

I'm also hoping it will make the engine last a bit better, but wouldn't be too surprised to learn that it doesn't. Anecdotal evidence says that it will. Empirical evidence hasn't arrived, at least not on my monitor.

I believe the folks who say the additives in synthetic automobile oil can make the clutch slip, so don't plan on finding out for sure.