Engine oil choice

Honest John Back Room » Technical matters
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Mon 29 Mar 2004 14:18
Engine oil choice - Greg R
I posted a thread before, and concluded that I was able to use car engine oil in my scooter which has a dry clutch. My mechanic also confirmed this.

However, my manual says I must not use an oil better than CD and must be better than API SAE.

I currently use a semi sythetic, and want to continue to use the same but in car oil form. I would prefer a 10W40 OR 15W40 oil.

Which oil make and type would be recommended in my case? Can I risk the castrol magnatec.

Also, considering my manual tells me not to exceed CD spec, what would be the consequences if I did exceed it.

Thanks again for all your help.

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Wed 31 Mar 2004 21:08
Engine oil choice - Andrew Moorey (Tune-Up)
A bit more info please, make/model?
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Wed 31 Mar 2004 22:06
Engine oil choice - Sooty Tailpipes
An oil can't be better (or worse) than API SAE as that is not a performance rating, they're the acronyms of the American Petroleum Institute and the Society of Automotive Engineers.

CD is an obsolete diesel performance rating by the API.
Even if an oil says API CD, it may be CF but as a budget brand, they couldn't be bothered with the hassle/expense of having it certified.

Weird !
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Thu 1 Apr 2004 14:13
Engine oil choice - Greg R
The scooter is a 125cc 4 stroke engine.
It is a Yamaha Majesty with 18,000 miles.
Used mostly on journeys longer than 3 miles.
A few long carriageway and sometimes motorway journeys (perhaps once or twice a month)

I am currently using Synthetic 15w40 motorcycle oil.
The clutch is a dry clutch.

Could I use Castrol GTX Mineral car oil as an alternative.
Would millers oil be a better choice?
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Thu 1 Apr 2004 16:09
Engine oil choice - Nortones2
I presume you have a common sump for engine and gearbox? This link might help: www.mobil1.com/motorcycle/index.jsp Although the clutch isn't an issue, the level of anti-wear and anti-corrosion additives might be relevant, as they say there are differences between car and bike oils.
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Thu 1 Apr 2004 16:12
Engine oil choice - Nortones2
BTW, not suggesting you need to use all-synthetic mobil 1! No doubt there is a semi-syn in the bike ranges of most oil makers if thats what you want.
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Thu 1 Apr 2004 19:12
Engine oil choice - trancer
You don't have clutch slippage to worry about so buy your choice of car oil in the recommended weight and use it. Mineral, semi or synthetic it won't matter in your case.
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