Bike specific oil vs car specific oil

[Gavin Buckle]

What is the difference between bike specific oil and car specific oil?

 

[daesimps]

Car specific usually have "friction inhibitors". This doesn't work out so well if you have a wet clutch, which most motorcycles do. Motorcycle oils obviously leave this bit out.

I think you'd be OK with car oil in a GS as it's a dry clutch (but not the new wet clutch WC version). However, I've never actually tried it and take no responsibility for the outcome if anyone was to do so.

Oh, and price too. Anything with motorcycle written on it usually costs twice as much!

 

[AberdeenAngus]

Dry clutch......you can use any shite.
Wet Clutch......use bike oil.

 

[(RIP) Tunneruk]

That's odd as every two stroke I've ever had I've always used common Castrol GTX 10 40 in the gearbox (naturally with wet clutch) .............

 

[AberdeenAngus]

I know a lot of folk swear it makes no odds, but I've had slippy wet clutch issues that were solved by switching to bike specific oil.
It probably won't make much difference a lot of the time but sometimes it does.

 

[FatAl]

I was once told by a sales rep of a large oil company that their 10/40 semi synth car oil was the same stuff as their bike oil, they just altered the packaging and charged more for the motorcycle oil. A pal regularly used to buy a 25 litre drum of the stuff and ran his Toyota Hi Ace diesel van, his sons Ford Fiesta, his BMW F650GS, Triumph Trophy 1200, Triumph Thunderbird Sport, and Ducati 750 on the stuff for years.
I also have run a Tiger 1050 and my current 900 Trophy on the same oil, also a Land Rover Discovery TDi (sold the landy a few yers ago) on the same car oil for years. My Harleys and all my BMW bikes including R1150gs were also filled with car oil as well.

 

[Time Traveller]

I know a lot of folk swear it makes no odds, but I've had slippy wet clutch issues that were solved by switching to bike specific oil.
It probably won't make much difference a lot of the time but sometimes it does.

Isn't this what is being said?

Wet clutches need bike specific oil, dry clutches don't (subject to the same legal disclaimer

as daesimps)

 

[Bendy toy]

My four cylinder Jap multi had bike oil when it was cheap but usually had semi-synth 10w40 car diesel oil. At 73K miles, the clutch started to slip under power in top gear. The friction plates were worn out. £50 for new plates and an hour's work had it sorted.

My other bike had 80 grade gear oil and a tiny clutch on the crankshaft. That never slipped either.

Something like Moly Slip is clearly not a good idea in a wet clutch engine but bike specific oil just seems to be an excuse to charge more money.