Oil and modifiers. Honda Pro GN4 oil, too?

Information and questions on GL1800 Goldwings (2001-2017)
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Motorcycle: 2005 GL1800

Oil and modifiers. Honda Pro GN4 oil, too?

Post by LK1LK1 »

This is NOT one of those "what kind of oil" should I use in my '05 GL1800. I have a basic understanding of 10W-40, the abundance of quality oil brands other than Honda Pro GN4, a necessity to change the oil at scheduled intervals, and use of the (preferred) Honda OEM oil filter, etc.

Still, I was wondering if most motorcycle oils, including the PRO GN4 oil from Honda, have the dreaded modifiers or "energy conserving" additives in some form or another. When I recently purchased a jug of Mother Honda's oil, (Pro Honda GN4, 10w-40w, SJ, MA, JASO T903- Black Bottle), I note on the back the manufacturer's identifying data about their oil: " . . . a unique blend of costly shear stable polymer additives . . . "

The owner's manual specific to my '05 Wing, which is probably similar to others up to the '17 model years, indicates a "suggested oil" of Honda Pro GN4 or HP4 "without molybdenum additives." The question for the day: Is an additive an additive, which is also designed for "energy conserving" properties? If so, what better oils (synthetic or non-synthetic) are now available without an additive at all?

I haven't changed my oil in the '05 Wing with the Honda Pro GN4 product, yet, and just wondering if maybe Motul 5100 oil (a blend) may be best because no "additive" identifier is listed with that oil. My Wing had one previous owner, the bike now has 24,000 on the odometer, and I'm unsure of what oil had been used in the past. It runs beautifully, which indicates very good past maintenance. Anyway, I'm not looking for an oil brand recommendation, just wondering about those "additives" and how to avoid additives entirely -- if possible. As always, comments and suggestions appreciated. Thank You.

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Re: Oil and modifiers. Honda Pro GN4 oil, too?

Post by AZgl1800 »

I never have used a Honda m/c oil.

I have always used a better alternative, and in the last 5 years, for me, that has been Rotella T6 5w40.
a pure synthetic, and no friction modifiers.

Clean clutch action, and nice crisp shifts.

Prior to that, I always used Delo 400 15w40 in my gl1500s

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Re: Oil and modifiers. Honda Pro GN4 oil, too?

Post by Viking »

All oils have additives. It is what helps oil perform to a better standard than the plain old oil would, like shear strength, resistance to evaporation, viscosity retention etc. Even fully synthetic oils are made up of synthesized esters and polymers AND additives. What you should be looking for is the "absence of friction modifiers" in the oil you use for a wet clutch application. Your Honda motorcycle oils fit this description, as does the mentioned Rotella T6, as well as Red Line, Royal Purple, Mobile 1, Amsoil to mention the synthetics, and also many other motorcycle oils by Quaker State, Valvoline, Havoline and many others that may or may not have any synthetics in them except for the additives (which by the way, are pretty much always synthetic additives) The mention of JASO MA/MA2 on a motorcycle oil product indicates that it is suitable for wet clutch use as it has no friction modifiers.
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