10w/40 car oil vs 10w/40 bike oil??

What's the difference? Besides the price. Halfords currently have part synthetic oil 10w/40 4 litres for £12 or 5 litre bike oil for £29. Is it a big no no using car oil for bikes? Genuine question.

The only oil you need to avoid is the stuff with additives......They can cause the clutch to slip on the bike.......

I use Motul 5100 in my bike......but that's just me......

The only bike I would happily use car oil in.. is a bike thats been designed like a car. and thats the BMW BOXER.. plus a few others.

in those bikes the engine and clutch are completely separate... so the oil doesn't need to do anything special for the clutch. also.. the gear box is separate too.. so it uses dedicated gear oil. (though for this discussion that doesn't matter)

the reason.. one of the reasons bike oil is expensive is the additives it contains to allow it to lubricate (and cool) a clutch without causing it to slip. (something car oils lack) and there are far more cars than bikes.. so they can justify a higher price due to not selling nearly as much.

I think it can be hit and miss using car oil in a bike.. get it wrong and thats a ruined clutch... or a bike that aint moving as it should. is this a risk worth taking for the sake of £17. (£17 if you must buy from halfords)

I think not.

I see, makes sense. Thanks for the information, I won't be taking a chance for a few quid saved just was curious.

The only oil you need to avoid is the stuff with additives......They can cause the clutch to slip on the bike.......

I use Motul 5100 in my bike......but that's just me......

Same here! Can't beat it.......got a few in from eBay a few months ago for €26 each delivered to the door!

I have used Castrol GTX in all my bikes including ZZR14 20k miles & 5 years and R1 36k miles & 10 years without any problems what so ever ..

I use motul 5100 too... and not just because it has a green bike on the front

Oh you may have just unknowingly stirred up a whole load on this topic .

I just stuck some of this in mine about a month ago, mine only takes 1ltr though so £10 for an oil change is more than reasonable for me .

http://www.halfords.com/motoring/motorcycling/motorcycle-oils/castrol-power-1-racing-4t-10w-40-motorcycle-engine-oil-4ltr?cm_mmc=Google+PLA-_-Motorcycling-_-Motorcycle+Oils-_-966200&_$ja=tsid:60494%7Ccgn:GoogleShopping%7Ckw:966200&istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istItemId=lwmliw&istBid=tztx&_$ja=tsid:35522|cid:427600924|agid:30036280924|tid:pla-229709635684|crid:106226716564|nw:g|rnd:4166999916844750209|dvc:c|adp:1o1&gclid=CjwKEAiA17LDBRDElqOGq8vR7m8SJAA1AC0_-8iuFf74DLcfyVdF1JY8WyEvPssYDRB9qooNipCixxoCYAfw_wcB

What's the difference? Besides the price. Halfords currently have part synthetic oil 10w/40 4 litres for £12 or 5 litre bike oil for £29. Is it a big no no using car oil for bikes? Genuine question.

I know a few guys who have used that particular oil in bikes with no problems.

Oh you may have just unknowingly stirred up a whole load on this topic .

both sides of this argument are very firmly entrenched in their respective positions and neither will give ground ..

but yes .. you are correct.. a can of worms..

ive heard there is effectively no difference, so long as its sheer strength and viscosity are the same it shouldnt matter what you use,

But im a weak consumer, i will buy bike oil like a good boy

The only oil you need to avoid is the stuff with additives......They can cause the clutch to slip on the bike.......

I use Motul 5100 in my bike......but that's just me......

Tango, forgive the daft question from me a new lad but do they state on the bottle if they contain those additives? I have not had to change my oil yet but if I use oil that is specifically advertised as being for bikes, will it not contain additives? man it can get so confusing! Cheers

The only oil you need to avoid is the stuff with additives......They can cause the clutch to slip on the bike.......

I use Motul 5100 in my bike......but that's just me......

 

Tango, forgive the daft question from me a new lad but do they state on the bottle if they contain those additives? I have not had to change my oil yet but if I use oil that is specifically advertised as being for bikes, will it not contain additives? man it can get so confusing! Cheers

I think one of the main culprits is that Magnatec oil.....but I think others have had problems with some different oils too.

Oil designed specifically for use in bikes should not have any additives in that would affect the clutch as most bikes use a wet clutch. The only question then really, is whether to use fully synthetic or semi synthetic. .....

The only oil you need to avoid is the stuff with additives......They can cause the clutch to slip on the bike.......

I use Motul 5100 in my bike......but that's just me......

 

Tango, forgive the daft question from me a new lad but do they state on the bottle if they contain those additives? I have not had to change my oil yet but if I use oil that is specifically advertised as being for bikes, will it not contain additives? man it can get so confusing! Cheers

I think one of the main culprits is that Magnatec oil.....but I think others have had problems with some different oils too.

Oil designed specifically for use in bikes should not have any additives in that would affect the clutch as most bikes use a wet clutch. The only question then really, is whether to use fully synthetic or semi synthetic. .....

Thanks man.. Oh dear synthetic? fully synthetic? Yet more confusion... I think my man at the bike shop said to use semi synthetic... Anyway, I am off to research this now, sorry for being a pain asking stuff but I do appreciate the help

Hey....ask away mate.....no probs at all......

Yeah....I'd be using semi synthetic in that bike......

This is what my manual states on oil!

No where in that does it state that I MUST use bike specific oil if it does then I have missed it!

I don't use bike specific oil I haven't for the last ten years and not had any problems at all

you need to check the API ratings of oils and what rating your bike takes

the oil rating for mine is API SG or higher! SG is obsolete and is made for engines newer than 1993 but older than 1996 where SH rating takes over!

That just shows that an oil made for engines between 93 and 96 is more than good enough for a 2001 engine!

with SG and SH now obsolete you move up to the next category which is SJ

So the max API rating I would buy for my bike is SJ

the grade 10w40 etc should also be in your handbook a lot of bike will take just about any grade depending on the climate and it is climate dependant 10w40 is the norm for the UK but do check the handbook as some engines require a specific grade

Now the bit that confuses folk is the JASO ratings

this is taken from a website on JASO ratings

Modern passenger car engine oils contain more and more friction modifiers. While this is the good thing for those segments (reduces wear and fuel consumption) it's bad for the motorcycles. At least for those motorcycles which use engine oil to lubricate their transmission and wet clutch. JASO introduced the MA and MB specification to distinguish between friction modified and non friction modified engine oils. Most four-stroke motorcycles with wet clutches need a JASO MA oil.

JASO MA

Japanese standard for special oil which can be used in 4-stroke motorcycle engine with one oil system for engine, gearbox and wet clutch system. Fluid is non-friction modified.

JASO MB

MB grade oils are classified as the lowest friction oils among motorcycle four-cycle oils. Not to be used where a JASO MA grade oil is required.

Basically its another body specifically The Japanese Automotive Standards Organization (JASO) saying yes this oil is OK to use

This is what my manual states on oil!

 

And do you torque the drain bolt up to 43 Nm then Stu

This is what my manual states on oil!

 

 

And do you torque the drain bolt up to 43 Nm then Stu

42 I think!

This is all probably very confusing to new bikers.

But there is a way to sweep all confusion aside... if in doubt use Motorcycle oil in your Motorcycle.

how simple is that?

Tango mentioned a brand 'Motul" and so i thought it might be useful to see what they have to say about this.

IS THERE A DIFFERENCE BETWEEN MOTORCYCLE OIL AND ENGINE OIL?

In a passenger car, the engine is separated from the gearbox and the clutch hence different lubricants are used which are specific for each mechanical component. For example, the engine oil in a passenger car can be formulated with a variety of friction modifier additives to achieve fuel economy benefits without causing any compatibility problem with the clutch. The gearbox lubricant is also specifically formulated to resist the very high shearing and contact pressures found when the gears are in operation.

Most modern 4-stroke motorcycles have their engine, gearbox and wet clutch combined together in the same unit and as a result all three components are lubricated by the same common lubricant.

Technical constraints for the 4-stroke engine, gearbox and clutch are very much different so the 4-stroke motorcycle lubricant must meet all of these: from Fuel Economy and high temperature stability for the engine - to shear stability for the gearbox - to anti-slip properties for the clutch!

This is why Motul are offering specific products for individual applications: whether it’s for your 4-stroke motorcycle or passenger car. By choosing the right product, you’re ensuring that the mechanical components of your bike or car are protected by a dedicated lubricant meeting the technical requirements set out by the Original Equipment Manufacturers.

So far in this thread.. and in most threads where "passenger car oil' is being promoted for use in bikes.. the emphasis has been on the clutch.. friction modifiers, clutch slip and so on. but.. if a clutch fails.. this isnt the end of the world. new clutch plates aren't prohibitively expensive and in most bikes replacement is fairly straightforward.

but.. theres another component thats just a little bit different. The gearbox.

By using passenger car oil in a standard 'unit' motorcycle you are using an oil to lubricate the gearbox that was never intended for this use. passenger cars.. and bikes designed in a similar way use GEAR OIL for the gear box.. oil that as mentioned in the quote above is designed to "resist the very high shearing and contact pressures found when the gears are in operation."

Car oil isn't.. car oil has a dual purpose.. to lubricate and cool a petrol burning engine.

So... I have to ask what evidence there is that this is fine in all circumstances. using engine oil to lubricate a gear box. and if its fine.. why do we have gear oil?

is the gear section of a unit motorcycle somehow different to a gear box in a non unit motorcycle.. like a BMW Boxer. and how are they different? The Boxer has GL5 80w90 gear oil specified.

why cant you simply use an ordinary car oil in that gear box.. like GTX. i dont know of anyone who would.. and yet this is effectively what you are doing.

Trusting an oil that was never designed for the use you are putting it to. to lubricate your bikes gear box.

Im genuinely interested to know why this is OK.

why the statement from Motul above is wrong or misleading.. and really there is NO DIFFERENCE, Car oil is fine for bikes.. fine for the engine, clutch AND gearbox. even though car engine oil was never intended to come into contact with a gearbox. (any gearbox)

I get emails stating that if I take this blue pill my wife will have the best night of her life!!

Somehow I don't think its true but that's marketing for you

I prefer to read independent testing rather than manufacturers claims

http://www.nightrider.com/biketech/oiltest1.htm

And I testing mobil 1 car oil faired better than bike specific oil

My question to those conducting these tests is, would they put Castrol GTX into the gearbox in a car, rather than gear oil? If its shear properties are good enough for a bike gearbox, then surely it'll be good enough for a car gearbox?

I also find glib statements like "we tested it in a motorcycle, and here are the results" annoying......what bike? Under what riding conditions? Over what temperature range? Putting car oil in a BMW Boxer engine and then testing it would be completely different to putting it in a 16000rpm 600cc supersports bike.

I started putting Motul 5100 in my Triumphs after reading on a Triumph forum that many people had used it and reported that the gearbox was noticeably less clunky when changing gear......and this has been my experience too. Triumphs are known for having clunky gearboxes, so anything that helps this is worthwhile in my book.... And, what oil did I use in my bikes before switching to the 5100?......Mobil 1......

At the end of the day you put whichever brand of oil you feel most comfortable with into your bike.......me?...I'm gonna stick with the Motul 5100......

My question to those conducting these tests is, would they put Castrol GTX into the gearbox in a car, rather than gear oil? If its shear properties are good enough for a bike gearbox, then surely it'll be good enough for a car gearbox?

worth repeating.

I read that article.. and straightaway noticed that it was almost 23yrs old.

really.

I tried to find information on the Author, or other articles/papers from Professor Woolum. of California State University... but nothing. nothing at all.

i was hoping for a serious discussion.. but it seems its easier to go down the conspiracy theory* rabbit hole.

never mind.

*Motorcycle engine oils are a con.

My question to those conducting these tests is, would they put Castrol GTX into the gearbox in a car, rather than gear oil? If its shear properties are good enough for a bike gearbox, then surely it'll be good enough for a car gearbox?

 

worth repeating.

I read that article.. and straightaway noticed that it was almost 23yrs old.

really.

I tried to find information on the Author, or other articles/papers from Professor Woolum. of California State University... but nothing. nothing at all.

i was hoping for a serious discussion.. but it seems its easier to go down the conspiracy theory rabbit hole.

never mind.

And relevant to the oil spec suggested for my bike!

"resist the very high shearing and contact pressures found when the gears are in operation."

from what I`ve seen / read I`m under the assumption that initially the oil is well up to the job; Castrol gtx in my case; of lubricating the gear box but that it degrades a lot quicker than a dedicated gear oil sae80 or similar ..

the answer bein a more frequent oil changing schedule 3- 4k miles ..