Duc Oil

[Martin Waterland]

I am changing from Mobil 1 High performance synthetic oil to maybe Amsoil for the yellow mistress and can't decide on which to give her; the 15W-50 racing oil or the 20W-50 motorcycle oil. I was just wondering what opinions are out there over my little quarry and what do YOU use?! Keeping in mind that we do enjoy a little romp or two on the sinful tarmac of course and not just the patrolled one.

[Sailor]

I am no expert but I have worked in the marine industry for the last 30 yrs as a tech. I did alot of research after finding that I could not get the shell advance oil here in Canada and was surprised at what I found. I think that if you are running a water cooled bike a 10-40 will service the machine just fine, remember that the oil will start out as a 10 weight when its cold and then act as a 40 weight once it is hot. If you are running an air cooled Duc then a 15-50 or 20-50 would be best as they tend to run a bit hotter than the water cooled machine. I read a comparison of 6 to 7 oils that were tested together (Amsoil test) and the over all winner was Mobil 1 and amsoil came third, surprised me. The one critical area that Amsoil beat all the other oils was shear strenght, the action of the gear box shearing the oil during circulation and lets face it with the jumble of gears in the bottom of the bike (transmission) I would like an oil that stands up rather well in that area. Most oils now a days are fine for lubrication and cooling but Amsoil gets my vote.

[The Goochman]

I am not a lubricants engineer, so everything that I am saying is hearsay.

I would (and do) stay away from any of the modern automotive motor oils. The API SL and other oils do not have the anti-additives that motorcycle engines need and the anti-friction additives are hard on clutches.

I run Mobil1 in the cars but I use the Mobil1 MX4T (10W40) in the bike. It is an SG / SH JASO MA rated oil.

I have an unfair advantage, because I live on the border. In Canada, they want $16+ a quart for the oil. In the US I get it for less than $10. Even still, I justify the cost to my self simply because I only change the oil once a year. I don't put anywhere near enough miles on the bike to have to do more than that.

As an aside, lawnmowers, lawn tractors, snow blowers and other power equipment should not be run on the SL oils either. Although it is harder to find, I buy an "ATV" oil which is SG/SH rated for those engines. The old John Deere is much happier with the old style oil.

If anyone is interested, I could probably organize a "bulk buy" of the Mobil1 if there is enough interest. You would have to pay the cost of the oil, and all duties and taxes, but it might still be worth the effort. It would have to be hand delivered to cut out the shipping expenses.

Dave G
aka The Goochman
lost in an open field somewhere near Sarnia

[Flyer]

Mobil1 MX4T is $13.27/L at the local (Canadian) WallyMart.

[gg996]

I run a 15/50 full synthetic in mine, gives you the same protection as a 20/50 when the engine is up to temp. and you get the benefit of a lighter viscosity when the oil is cold. The oil will get to the top of the engine a bit faster with the 15/50.
If you are going to be at the track or if you ride the bike hard, you might want to consider a 10w60 full synthetic.