Is there any problem with putting car oil in a bike engine ?
I’m due an oil change and the greedy lump needs nearly 3 and a half litres of the stuff :w00t:
Just thought it might be easier to get a big bottle of car oil rather than the piddly little bike bottles. Any problems with this ?
no…
errrrrrr no…
and err no… 
friction modifiers bla bla bla…
hein gericke do bike oil in 4 liters for around 14 quid sometimes you even get a free filter with it
buy bike oil in the big can 4ltr.
STEP AWAY FROM THE CAR OIL!!!:w00t:
As Adz says you shouldn’t use car oil unless you want your clutch to slip all the time;)
halfords do a 5litre tub for a score, so you get extra for topping up in between services. no probs with it on my high mileage bandit 6.
As long as it is the same grade as recomended by the manufacturer then there shouldn’t be a problem. Does the manual specify synthetic or semi-synthetic. Put the wrong stuff in and you could have clutch problems. ie slip.
Always buy in bulk. It’s cheaper and easier to handle.
Best of luck 
I disagree with the first bit, they’re designed for different tolerances and to work at different loads… how many Citroens and REnaults and Fords do you know that rev up to 12000 Plus…?
Yup, see your point.
Just the workshop manuals only specify a grade, must meet certain specifications, but not a brand and they certainly do not say “motorcycle” oil. And if you use “Motorcycle” oil as sold in Halfords then you will reduce the lifetime of the engine, it’s oil, not the top notch stuff that you may want in your beasty.
Like I said as long as it meets or exceeds those requirements then there should not be a problem. Different bike shops will use different brand oils, but they will all meet or exceed manufactures recomendations.
You pay your money and you make your choice. Personally I would like to pay that little more and know I have the right stuff rather than skimp and worry. :w00t:
Polymers! You cant put car oil in bikes. Think about it, cars dont run the same oil in their engines and gear box? The polymers in engine oil would get mullered passing through the meshing teeth in a gearbox!
Yikes ! Glad I asked the question first before going and buying car oil ! Still gotta lot to learn 
Cheers for the replies !
just to be different, I put car oil, specifically magntec 10-40, in my bike engine, and 75-90 in my gear box (final drive gets the same as the gear box) I don’t experience clutch slip, well I would if oil got on it 
Castrol have a neat little “oil finder” on their website http://www.castrol.com/castrol/castrolhomepage.do?categoryId=3205
look under "other engine oil recomendations "
I know a few people who use car oil in their bikes, but no way I would.
Gearboxes literally rip the oil molecules of car oil apart because they are not ‘shear stable’
I buy the Hein Gericke stuff - just rebadged Motul stuff and at £11.99 / 4L is actually cheaper than all but the cheapest, crappest car oil.
The important standard to look for on bike oils is JASO MA - this is a japanese standard specifically for wet clutch applications.
Excuse me but car engines and gearboxes commonly share the same oil these days. Where you been since front wheel drive went main stream in the '60’s?
I agree about the engine speed bit though and it’s worth noting that modern cars are also commonly built to sloppier tollerances than bikes and “designed” to use oil.
The specification is everything’ so get anything that matches the manufacturers numbers. If you get a match on the spec. it doesn’t matter much if it’s marked for industrial use and sold by the pound.
Oh, when I say match, I mean an exact match including all the little numbers and letters on the end.
There’s more to oil than just lubrication. It’s got to lubricate as well as pick up bits of metal and carry them to the filter, there are detergents, anti-wear agents, anti-foaming agents, corrosion inhibitors etc.
At the top level: you have to pick the right type of oil for the type of engine. Diesels are different from petrol. There’s division along 4stroke/2stroke also.
There’s the viscosity of the oil, which is important from the perspective of how easily it flows through the engine. There’s two measures of this in the numbers (check the numbers on the bottles) which are from cold start and at engine operating temp. So having too “thick” an oil for starting might mean that oil isn’t flowing properly while the engine is cold which means damage to parts.
So that’s what the 5W-something or 10W- something is all about. You might find that your manual gives you some options usually. The eternal battle with engine oils is having one that is easy to flow while cold, but still thick enough at temperature to lubricate well.
It gets confusing when you have the multi-grade stuff and they have different letters/numbers for things.
Then you’re onto the notion of full synthetic, blends, etc. Full synthetic = more expensive, better performance in pretty much every measure (viscosity at low and high, oil life, resistance to breaking down etc). Mineral/natural/conventional oil: cheaper, work well for most engines, most common for cars etc. Semi-synthetic: meets in the middle somewhere, useful for motorbike engines that don’t need quite the performance of a fully synthetic oil.
During engine break in on my 675 they used quite a thick natural oil or a semi-synthetic (I think) and the idea was that it was “goopier” to suck up the early bits of metal that would come out of the engine during break in. Then they recommend mobil 1 fully synthetic. So for break in it was important not to switch to full synthetic too early or else it may actually damage the engine. So kinda amusing when people talk of taking care of their engine changing their oil after the first 100 miles and going to the “normal” fully synthetic rather than using a thicker oil for the first 500 (as they’ve probably done more harm than good).
My old bullet proof GS500 used to burn a bit of oil, I think at one stage there I’d topped it up with a variety of car oil, motorbike oil of different grades etc. It survived ok, but then again it wasn’t getting hammered around a race track. Better than riding on empty though. For a sports bike revving like mad the oil has to put up with a lot more. So if you’re stuck in bumsville and the oil light comes on and you absolutely have no choice: read the manual for the ranges of oils you can put in it and try and find something within that. If you’re in a colder part of the world the lower number is going to be more critical. Also if it’s just a bit of a top up it won’t be as critical as filling the thing from empty. If in doubt and just needing to “limp home” I’d say car oil will suffice (hell, my GS500 didn’t blow up when I did that one time), just take it easy on the way home, keeping engine revs low, then change the oil as soon as possible. But it’s doubtful you’d be unable to find motorcycle oil at the nearest service station really.
I certainly wouldn’t mix oils on my 675. In general unless you’re going to drain it completely you want to be putting the exact same oil in (in case the detergents/additives from one don’t go well with another). So if you get it filled at a shop, ask them what type they put in, or tell them what type you want put in.
Anyhow, I hope I’m not misinformed with any of the above, comments welcome.
That’s what I said 
or tried to say Anyway what everyone is saying… Get the right stuff :w00t:
Just stick some car oil in it!!
I was a commercial vehicle mechanic up until a couple of years ago and I’ve always just used the oil at work that we use on the vans and trucks as it’s free :w00t:
I’ve used this oil in all my bikes from a Bandit 1200 through to a GSX-R600 K6 and in doing probably 15-20,000 on each bike I’ve never had any mechanical engine problems and on servicing the bike and checking valve clearances etc there has never been any signs of excess wear.
I’m sure that there is some scientific reason why we should buy bike specific oil but in my non-scientific tests I’ve yet to find a good reason
Picked some up at lunchtime, Rock Oil motorbike oil, 18 quid.
Cheers for the advice, interesting to hear all the different opinions !
Last gearbox oil change I did was a Morris Oxford, so forgive my ignorance 
I don’t actually have a car licence, so only do simple servicing on SWMBO’s verhickle.
