I've been running Amsoil in mine. No problems at all and no slipage. The Oil is pure synthic without friction modifiers. I also run it in a honda rancher es 4x4 that has a electronic thumb shift. It kind steep price but its made for wet clutches.\ I also run it in my truck engine,transfer,trans,rear and front ends. they do say though when running amsoil in a limited slip rear end is NOT to use any additives(friction modifiers). I have 118,000 miles on it not so much as a burp!!!! the one thing i have notice is the ds and truck run cooler and start easlier. but this is just my observations.

2001 ds650
2002 honda rancher es 4x4
1997 f-150 [img]i/expressions/face-icon-small-happy.gif[/img]

 

Castrol GTX 10w-40 for me also.

 

I run Klotz techniplate 10X-40 full synthetic. That's what my dealership recommended. I was worried about slip too. I talked with Klotz about it. They said they tested DS's & this oil worked great. So far so good.

About $6.50 a quart, I run the Honda oil in the 400. Everyone likes that oil.

I noticed Autozone carries Mobil 1 motorcyle oil for wet clutches....

 

I think the point is getting kinda missed by some.
There is no doubt that synthetic oil is a better lubricator that conventional petroleum products - it has been proven time and again - it is slicker, and reduces wear better - I've even proven this myself through vibration analysis of several types of equipment, always showing less vibes and smoother running of equipment using synthetics.

Only problem is that full synthetics can make SOME clutches slip under CERTAIN riding conditions - particularly speed shifting in a drag. Anybody using synthetic oil with stock springs on their DS will experience slip if they ride it like I do.

I run an oil that is semi-synthetic (HP4), for better protection and wear resistance than convetionals, that is also designed to help combat the clutch issues caused by full synthetics. I do use Valvoline Durablend in my truck, cars, lawn mowers, even my Arctic Cat, but not in the DS.

Regular oil Vs. Motorcycle oil discussions are as old as riding itself - you can never convince anybody to change their minds or opinions, but oil aint just oil - in this day and age it is possible to engineer products for specific functions.

 

Castrol GTX 10w-40 for me, too, works awesome, never slipped

 

Was running Castrol and burned up my clutch. Switched to Redline ( I know the local distributor) and have not had a problem since.