By Litre1 on Thursday, October 10, 2002 - 07:57 am:

I spoke with a rep with Aprilia USA this morning about oil brand and viscosity selection. He said obviously the 15/50 full synthetic is what is recommended by Aprilia, but the most important point is consitancy of brand and type. He said the best way to ensure good engine wear is to stay with the same brand (Golden Spectro semi-synth in my case), so the additives are always the same. Some brands put additives that contain metals 'a' and 'b', while another brand contains metals 'b' and 'c'. And as we all know, some metals do not enjoy being grouped together (this is known as corrosion). So, the best way to select an oil (if you can't go by the book) is to choose by availability. He said changing viscosity is not a big deal as long as you stay consistant with brand and type.

As far as synthetic vs. petroleum-based, synthetic will be better for a long engine life. But who is concerned about puting 200,000 miles on their bike? Petroleum-based oils will give you more than enough protection.

As for the clutch slippage, the Aprilia guy said it has to do with the pneumatic clutch, and severe usage. The slippage under extreme stress is a trade off for eliminating wheel hop under engine braking. He didn't offer a theory about what kind of oil would help minimize it.

Hope this helps (at least put your mind at ease--I know it did mine).  

By 10451238 on Thursday, October 10, 2002 - 10:43 am:

Not sure about the same brand thing. Surely if you fully drain the bike it doesnt really matter.

I have always had good experiences with Putoline fully synthetic. Gave very good gearbox lubrication and looked as clear as it went in when I removed it 8 months later.  

By Befbever on Thursday, October 10, 2002 - 10:57 am:

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Quote:

As for the clutch slippage, the Aprilia guy said it has to do with the pneumatic clutch, and severe usage. The slippage under extreme stress is a trade off for eliminating wheel hop under engine braking. He didn't offer a theory about what kind of oil would help minimize it.

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By Bob on Thursday, October 10, 2002 - 11:57 am:

Exactly Bef,
Why would they bother with designing a new one then. They told me that the friction plates sucked to much oil and after a while start slipping.  

By Dave on Thursday, October 10, 2002 - 03:32 pm:

I've just been told the same about sticking to the same oil - different manufacturers use different chemicals so the important molecules that do the work are different and don't work properly together to some extent.  

By Chuzo on Thursday, October 10, 2002 - 04:08 pm:

Gave very good gearbox lubrication and looked as clear as it went in when I removed it 8 months later.

I might be wrong but I remember reading some Castrol literature explaining that motor oil traps oxidized compounds and other impurities changing its color in the process and if it didn't change of color one should not trust that oil as a good one.

Corrections are welcomed 

By Tokas on Saturday, October 12, 2002 - 04:50 am:

When I did my 7500 km service at a garage known for their knowledge and good service for Italian bikes, they recommended the EXS 10W-50 oil from Bel-Ray. It's fully synthetic, multi-grade 4-stroke oil "developed in world championship superbike competition".

I've had it now for 1000 miles and I'm happy with it. My friends have been using it in their Duc 748 and Duc 855 for years, with no complaints.