difference between car oil and motorcycle oil

[bourne92]

im fairly sure that i know the answer to this already but just after some confirmation that i am a tool haha.

Well i work in a garage and we stock loads of shell 10w40 oil, so i found that the cbr400's take 10w40 and thought brilliant, free oil change. My stupidity only hit me as i was riding it after the oil change, it got hotter than it usually does, but not hot enough to kick the fan in and it sounds very tappety now.
So am i right in thinking that oil intended for use in cars is different to oil sold for bike's? even though they're both rated 10w40

[bikemonkey]

Very different.

Car oil has alsorts of additives in it that do no good to bike engines, get it out and get some proper stuff in there.

[bourne92]

thought so, thanks mate. Just hope nothing is damaged, only done 20miles since the oil change (one journey). Going to get some proper motorbike oil tomorrow.

Thanks for your help pal

[Kurlon]

Unless you put some real shite in there, 10w40 is 10w40. The differences as noted are the additive packages, automotive oils will have friction modifiers in them as a means of improving a vehicles MPG. Those same modifiers tend to not play well with clutches resulting in slippage in extreme cases. Ideally motorcycle oils use a base package that will hold up to sheer forces (transmission runs in the same oil on a bike, not the case in a car) longer but that's not always the case. None of that would explain the change in your bike's behavior in such a short amount of time.

[bourne92]

It was shell helix oil so good stuff, I swapped it out for some 10w40 motorbike oil yesterday. Riding work today it did get hot again but I noticed the fan dosnt kick in until fairly close (closer than im confortable with at least) to the red, it only gets hot in traffic and cools down again once im going and some air is flowing through, maybe its always being like that and ive just never notcied until I did the oil change or maybe its because ive never ridden it in hot weather before. As for the tappetting I noticed the exhaust it blowing at the back box and I know that can sound tappetty, so ordered a gasket, try that see how it goes. Thanks for setting my mind at ease, had a horrible feeling that oil had completly knackered the engine!