So in my (desperate) search for some new oil for the bike today (and only coming across insanely expensive products the likes of which I do not require nor can afford) or finding the not-so-local super cheap auto (the local local one doesn't stock any motorcycle oil, the not so local one NORMALLY stocks a whole range but everyone seems to be having an oily christmas or something)... anyway SCA didn't have what I normally get (good 'ol shell for the CB... was going to experiment with some speccy-er stuff from shell based on a mate who worked for years as a lubricant specialist for a number of companies... though admittedly on industrial manufacturing plants not motorcycles) when I started wondering... what about automotive oil of the same weight? What's the difference? Is there one? Curious, though not overly tempted to wreck my shiny, fast, near replacement for a woman's touch of a motorcycle by being ignorant + stupid, I tentatively asked an intelligent-looking member of staff if he was aware of any differences. He admitted to not having a degree in organic chemistry (though mind you I only have 1/3rd of one so that hardly counts) but told me he'd heard from a friend that the wet clutches of a bike have a tendency to freeze if automotive oils are used.... doubtful as to how this would work, but again not willing to skimp the 20 bucks, I bought a slightly more expensive than normal oil (that the bike seems to love reguardless). Tonight, browsing the web and cursing my friends for not being the night owls that I am, I came across this: www.nightrider.com/biketech/oiltest1.htm Though no exploration into the realm of catastrophic failures is made, it makes for an interesting read if nothing else. What do you guys think? Does anyone here indeed use automotive oils? Does anyone have some first hand experience with catastrophic failure of engine components from using automotive oils? Or are we just being elitist?
In a car the engine is always separate from the gearbox so they have separate \ tranny oil for each. In car oil, there is more "friction modifiers" to help lessen the amount of friction on engine components and improve fuel economy. These friction modifiers that are added to automotive oils are what cause serious damage when used in bikes. The friction modifiers clog the clutch plates in a motorcycle's gearbox causing serious clutch slippage. To make motorcycles compact, manufacturers combine their engine and gear box into one casing. This means that everything is lubricated by only one type of oil including the valves, piston, transmission, because of this, we change our oil more frequently than a car. Motorcycles require very little and/or no friction modifiers to help improve clutch friction and to prevent clutch slippage. But to make up for this lack of friction modifiers, motorcycle oils use higher levels of anti-wear additives such as ZDDP, also known as phosphorous, to limit engine friction and wear. Since motorcycle oil has extra anti-wear additives and is lubricating so much more than automotive oil, you can expect to pay heaps more for bike oil. Cheers Chris
That would explain the story of a frozen clutch I heard, though the article I linked (though it states no sources for this actual claim) DOES adress ZDDP Is this different in Australia? DO we allow more ZDDP in our motorcycle oils?
