I use Delvac or Rotella 15w40 oil for diesel trucks. There are no friction modifiers that damage wet clutches, and it has plenty of zinc like motorcycle specific oils do. And it's cheap.

Charles.

I have heard the stories about those JASO MA-certified diesel oils such as Shell Rotella and Delvac, but those seem to be USA-specific. I think the Shell Rotella lineup isn't even brought over to Europe, replaced by Shell Rimula instead, which doesn't have nearly as many suitability endorsements.

Sure, I bet that basic mineral oils (esp. those "heavy duty diesel" or "fleet/multivehicle" ones are so, well, basic, that they don't contain any fancy friction modifiers, but JASO certs cost so nobody does them if they don't have to.

Rotella isn't JASO MA certified, because it's an oil for diesel trucks, it just happens to work well. Just run 10-30 or 10-40 motorcycle oil, that's the oil that Honda specifies, and they're Honda clones. You're over thinking it.

I was under the impression that the big deal specifically with the Rotella was that it was actually JASO MA/MA2 certified, at least certain grades of it are (like the T6 15W40).

Perhaps this led to -probably safe- misconception that all diesel oils are also suitable for motorcycle use.

All I know is the clutch in my V65 Magna doesn't slip using Rotella T 15w40 or Delvac 15w40. If the V65 clutch even gets near regular automotive oil it will slip, and these two have worked well for me for years.

Charles.

https://rotella.shell.com/en_us/prod.../t4-15w-40.pdf

SPECIFICATIONS AND APPROVALS
Shell ROTELLA T4 15W-40
API, CK-4, CJ-4, CI-4 PLUS, CI-4, CH-4; ACEA E9, JASO DH-2,
MA/MA 2; Caterpillar ECF-2, ECF-3; Cummins CES 20086; DDC
DFS 93K222; Deutz DQC III-10 LA; MACK EOS-4.5; MAN M3575;
MB-Approval 228.31; MTU Category 2.1; Volvo VDS-4.5

After break in.

https://rotella.shell.com/en_us/prod...synthetic.html

Do you have any issues with clutch slip; or does it slip at all??


When I was deciding what oil to get, well, stick with; everyone said that for the engine setup / clutch setup that synthetic would most likely cause a slip or eventually just slip while in gear.. I'm just wondering the validity of that, especially with how many use synthetic..



I may or may not go out in the winter. I'm a little undecided just because of the cold. But, oil weights / weather aside - I'm just trying to see if there would be any benefit of synthetic over mineral oils - and I'm not exactly sure of the engine you have compared to mine. I believe you have done some internal mods; maybe? It is a Zongshen 250cc, SOHC though. I'm right at 220mi. on the ODO.. was actually thinking about going to synthetic around the 500mi. mark? Or, what mileage would I need to be at before making a switch to synthetic? :hmm:

No real benefit of synthetic, and big detriments IMO. Most synthetic is too thin. 5W oils are great for motors that are specifically designed for them. Zongshen bikes are not. 5W synthetics are made for high performance machines with very tight tolerances... which is not what the Chinese are producing at present.

Charles.

Gotcha - I'll stick with what I've got then lol

:thanks:

Incorrect. Rotella T4 and T6 both show the JASO ratings right on the bottles and on their website as well.

A bit of wrong here. A couple of benefits to synthetics include higher lubricity without the need for friction modifiers and molecular stability under higher stress conditions.

Most synthetic is too thin? The viscosity rating disagrees with you. 5W viscosity is 5W viscosity, regardless of if it is synthetic or mineral oil. That rating is literally how well the oil flows due to its "thickness" or more specifically it's ability to flow due to internal friction.

As far as 5 weight being too thin for the motor... that depends on the air temp. Plus, we need to consider that we are not running straight 5 weight, but a multiviscosity oil. It behaves as a 5 weight when in cold conditions, hence 5W, W meaning "Winter." Once hot, the oil will then behave as the other half of that viscosity rating (30, 40, etc). So a 5W-40 will be thinner at 32 degrees than a 15w-40, but at 200 degrees they will both behave as a 40 weight oil.

I run both of my bikes (and many previous ones) on synthetic oil. I run my VFR1200F on Motul 4T 7100 10w40 synthetic, and I run my Hawk on Rotella T6 15w-40.

People that say synthetics cause clutch slippage are spreading false information. This myth was borne out of either sheer ignorance, or somebody used an automotive grade synthetic that contained friction modifiers in their bike. Many factory bikes now come with synthetic oils, especially the very high powered bikes.

What causes synthetics to be more "slippery" than mineral oil has more to do with the molecular side of things. Being more stable, and thus maintaining lubrication under stress when standard oils start to lose viscosity. The actual effect on the coefficient of friction on the fiber and steel plates in the clutch is minimal.

Just a fun fact for you, but there is a threshold for oil where it starts to lose viscosity as it gets too hot. This is why race engines run such heavy oils and your toyota corolla gets by with 5w20. Your engine doesn't get hot enough to degrade the viscosity, nor does it's shear strength fail under high load.

Now, all of that said, is there a NEED for you to run synthetic? Not at all. These bikes will chug along just fine on conventional oil. I just choose to run T6 because it doesn't cost that much more than T4, just a couple bucks an oil change, and it does actually hold up a bit better long term allowing me to stretch out the oil change interval, especially with the oil cooler. I basically have double the oil change interval now because of those two factors.

Good to see Megadan's logic back around the forum, it stimulates thought. I agree, regular oil these days is very well made and you probably would not see a difference, but a synthetic oil has so much more resistance to heat among many other qualities for what you can pay for the Rotella full synthetic why not go with the best insurance? When I am running my bikes hard, it feels good to know I have synthetic splashing around in the case. And the best thing is for the money you can change it often. CG strong, ride hard!

Some observations about oil weights and their "syntheticity": an oil with a Winter weight of 10 or below, e.g. 5W40 or 10W40 will almost always be at least a synthetic blend/semi-synthetic or better. Stuff that goes as low as 0W or 5W, regardless of what the "hot" weight is, is typically fully synthetic.



Oils with an extended weight range such as 10W50, 15W50, 10W60 etc. will also almost always be fully synthetic or at least synthetic blends. You simply cannot get that much variability with just refined mineral oil.


That being said, I've seen more "traditional" weights such as 15W40 or even the venerable 20W50 (a staple of mineral oils) being produced in semi-synthetic or fully synthetic variants as well.


And yes, already a semi-synthetic oil exhibits much better durability and longevity when used in those small, punishing motorcycle engines. Mineral oils just seem to break down on me after about 500-600 km: cold viscosity gets thicker, hot viscosity gets thinner (exactly what you DON'T want!), clutch gets grabbier and less progressive, gearbox gets noisier, stop-and-go riding in even moderate temperatures becomes fatiguing etc. A decent semi-synth easily goes to 800-900 km before any noticeable differences, and operation is overall smoother. I assume a fully-synthetic would do even better, but then there might be issues with older oil seals, gaskets and the such.

I get most of my oil for free, so that leaves me room for experimentation.

I was running Gulf 15w40 bulk in the bike since break in. Overall, it wasn't bad but seemed to really start to lose performance after about 250-300 miles. Usually noticeable in the way it shifts (or doesn't). As it's gotten cooler, I switched to 5w40 T6, and the shifting smoothness really took a hit and it seems like across the board, hot or cold. I will go back to a 15w40.

Here's the rub, though. I had gotten a bottle of the new Rotella 15w40 T6 back in August. Instead of "wasting" it on the Hondoid, I used it in my V-Star 1300. These bikes are known for being buttery smooth and quiet *all* the time. I promptly took off and put 2100 miles on it in a week on a tour of New England. The oil now has 2600 miles and still feels like the day I replaced it. The Bel Ray conventional I was using before usually started to feel worn after 1000 or so. The feel is so good on this 15w40 T6, I'm considering doing a UOA just to see where it's at. I'd almost feel comfortable with a filter change and a top off if I was a little less blessed with free motor oil!

So, my 2 cents worth. This CG engine is basic, it's internally sloppy by design, and only in the most extreme cold or cold take-off situations do I feel a 5w would be of any benefit. It gets the oil moving quickly, and has very little to restrict it's flow as there is no filter. I'm ready to ditch the 5w in the bike now and just switch to 15w40 T6 across the board in all of my bikes, all seasons.

A good 15w40 oil (not the Gulf junk I have) will serve you quite well. Synthetic or conventional. Your choice. Synthetic will just be a little better, for the well established and tested reasons that synthetic is always better. At about $22 a gallon, you get 4 oil changes. That's pretty damn cheap, too. Conventional being even cheaper. Wally World is your friend.