NancysToy
Motorbike Professor
I have used Amsoil in all my other bikes, even when the HD dealers tried to tell me that it would void the warranty and cause the roller bearings to slide...lol.
I never went over 3K and just never would on a V-Twin, due to the engine temps and heat produced. Now on my Goldwing I would go 6K no problem for a 6 cylinder car engine, no problem.
I would say that BRP would frown on anything beyond the recommend maintenance. Again 2500-3000 is my limit on two cylinders V or parallel...
Air-cooled V-twin and liquid-cooled V-twin are far different animals. The water-cooled engine stays a lot more uniform in temp, without the extremes of the air-cooled variety. Apples and oranges, I'm afraid. It is contamination from the wet clutch, as well as oil shear from the transmission that worry me the most. I would consider stretching the interval by 30% on a trip, if using full synthetic, but I would never go much farther.
No matter how good the oil, I never exceed manufacturers' recommendations if I can help it...especially while under warranty. No sense in tempting fate. I cannot save enough on oil to pay for a single warranty claim. Although the oil is not likely to cause an engine failure, a dealer could easily blame the failure on the lack of oil changes, and you would not have a leg to stand on. A warranty is a contract, and the customer has obligations, as does the manufacturer. One of these obligations is timely oil changes, according to the manufacturer's schedule, not the oil company's.