I have just discovered that when I last had the oil changed by a "mechanic" that he used car engine oil.
This caused what sounded like a tappet rattle but was actually the oil causing a hydraulic pressure build-up because the "mechanic" had put 5.1 litres into my ST instead of 3.9 litres.
Here is what I have found on the net regarding Oil.
Do not use Car engine oils in Motorbikes ...
Another one of my wiki pages ..
Car oils in Bikes ?
A lot of people have used engine oils meant for cars in their bikes and claim that there is absolutely nothing wrong in doing so since they cannot find any damage .
The damage is certainly not perceptible to you , but such engine oils undoubtedly damage the internals . A brief intro for those who don't want to read the lengthy post-
Most car oils are rated as API SF, SG, SL and the latest being SM (not yet avail in India)
These ratings are given once in three years and each new rating is an improvement over the previous one . The ratings are in the same order as the English alphabets . The newer is better . so SM is better than SL and SL is better than SG etc.
Car engine oils have friction modifiers in them . Motorbike engine oils - specifically four stroke engines with a wet clutch multi-plate set-up do not require oils with friction modifiers . Modifiers can increase or decrease the friction , but most of the modifiers used are to reduce friction.
In my earlier post I wrote to synthetic oils I have already explained why synthetic oils sometimes cause the clutch to slip .
Recap - Synthetic Oils
Recap - synthetic oils meant for cars when used in bike will cause clutch to slip because car synthetic oils have friction reducers which are not required in wet clutch motorbikes. The oil in wet clutch motorbikes need the oil only as a coolant not a lubricant . The lubing is required for the engine and not the clutch in this case. Hence use only specially formulated motorbike syth oils and not Mobil 1 etc in bikes. Synthetic oils are available for motor bikes specifically - ex Motul 300V.
Bike spec oils
Coming back - The SL and SM ratings have friction reduction modifiers which are required in cars but for the same reason as explained above, they are not suitable for wet clutch multi plates . Apart from the clutch it is reported to cause damage to engine as well . The links for all of this is given below.
The only API ratings that are applicable to most Indian motorbike engines are oils that are of API SF or SG ratings . Check any bike manual and most of them are of this specification .
The only body which is rates oils for use in 4 stroke wet clutch bikes is JASO - Japanese Automotive Standards Organisation (
http://www.jsae.or.jp/e07pub/jaso_e.html) . There are two ratings from JASO - MA and MB . MA for hi friction engines and MB for low friction engines . MB is never recommended for any Indian bike . As explained previously its for low friction application - not for our kind of bikes.
Always use JASO MA grade oil . It doesn't matter what the API rating is , if its JASO MA - you are guaranteed that the clutch won't slip and as long as the oil is not API SL and above you are guaranteed that the oil is not harming the engine. All the relevant links are given below.
Resarch from the Net
From
http://www.sportrider.com/tech/146_0308_oil/Rather than continue to rely on specifications dedicated to auto mobiles, the Japanese Automotive Standards Organization (or JASO) developed its own set of tests specifically for motorcycles. JASO now publishes these standards, and any oil company can label its products under this designation after passing the proper tests. JASO offers two levels of certification, MA (high friction applications) and MB (low friction applications). JASO requires that the entire product label be approved before it can carry its label. If a label does not have a box with a registration number above the MA or MB lettering, it could be non approved oil whose manufacturer claims its products meet JASO standards when it may not have actually passed the tests.
These standards also include a test specifically designed to measure the oil's effect on clutch lock-up, as well as heat stability and several other factors related to motorcycle engines. Our advice here is pretty simple: Read your manual, and if it calls for an API SG oil, use that. Don't substitute a higher API designation oil like SL, because it will contain less of some additives like phosphorus, and it may contain other additives that will yield higher fuel economy in a car but could cause slippage in your clutch. (More on that later.)
Why should you not use car engine oil in bikes
http://www.math.uwaterloo.ca/~rblander/oil_opinion.htmlNone of the arguments I've provided so far have relied on the familiar old ideas about motorcycle engines being harder on oil than car engines that are so contentious in the debate. What I've presented so far is sufficient to show why you should not use modern typical car oil in typical motorcycles. But let's at least mention some of the old reasons.
Zinc from ZDDP. Zinc is an anti-wear additive typically found in motorcycle-specific oils at higher levels than in car oils. The chemical that provides it is ZDDP, zinc alkyl dithiophosphate.
Phosphorus from ZDDP. This ingredient is helpful for preventing gear wear. It is used in motorcycle engine oils to help protect the transmission. But phosphorus is bad for catalytic converters, so car oils, which are not used to lubricate transmission gears, have very little phosphorus.
Viscosity. The common car oils are 10W30 or lighter, like 5W30 and 10W30. These are too thin for motorcycles. Most motorcycles call for 10 W 40 or heavier in order to support bearings, resist against consumption due to volatility, and so on.
The debate over factors such as these often revolves around questions of the degree to which your engine actually experiences the extreme conditions that specialized formulations are intended to protect against, the degree to which simple use of ordinary oil with a much higher frequency of replacement would offer similar protection, and the relatively high cost of motorcycle-specific oils.
Anecdotal stories abound, but as single data points, they're not worth much. When the motorcycle manufacturers themselves, who have no vested interest in whose oil you buy, warn against the use of car oil for specific reasons, and when the oil industry itself acknowledges this difference in requirements by responding with a new set of standards for motorcycle-specific oils, I think it is pretty safe to put your trust in the recommendation that you should not use the modern SL "Energy Conserving" oils in your motorcycle......"
More good reasons why you don't want to use car oil in bikes
http://www.thumperfaq.com/oil.htmQ: IS AUTOMOTIVE MOTOR OIL BAD FOR A MOTORCYCLE?
A: Not bad, but probably not the best. Why not? It is designed in reverse order to a motorcycle oil. The priority hierarchy of automotive motor oil is: (1) Maximize fuel economy. (2) Reduce emissions. (3) Offer protection for the moving parts. Today's automotive motor oils do not have the same degree of extreme pressure and anti-wear agents that they did just a decade ago."
Q: WILL AUTOMOTIVE MOTOR OIL HURT MY BIKE?
A: It could. If you're using an automotive motor oil in your racing four-stroke, you're not buying the best protection. An API SL oil is missing vital anti-wear components: the most common being zinc, phosphorus and sulphur. These agents are harmful to the catalyst that is used to diminish the level of pollutants in auto mobile exhaust.
Q: WILL AUTOMOTIVE OIL HURT MY CLUTCH?
A: Yes. The friction modifiers in motor oil improve fuel economy by making it easier for the gears, bearings, pistons and rings to slip, slide and turn inside the engine. Unfortunately, these friction-minimizing agents also make it easier for the clutch in a motorcycle to slip. If you are using automotive motor oil in your bike, apart from CRFs, you are losing hook-up and acceleration, as well as reducing the life of the clutch.
Q: WHY SHOULD I MEMORIZE THE ACRONYM "JASO"?
A: As soon as it became apparent that the American government was mandating economy over protection, the Japanese Automotive Standards Organization (JASO) developed a standard specifically for performance four stroke motorcycles. JASO designates two different four-stroke oil classifications: MA and MB. The MB oil is low friction and the MA is sans the friction enhancers.
Q: WHY ARE MOTORCYCLE SPECIFIC OILS BETTER?
A: Motorcycle specific oils are pumped up with five times the anti-wear, anti-scuff and extreme pressure additives of regular motor oil. As an added plus, motorcycle oil does not include molybdenum disulphide and other friction modifiers that wreak havoc on clutch performance.
Maxima, a popular motorcycle oil supplier, starts with an API SG Service Category base oil, the last formulation that wasn't regulated as to the amount of zinc-dialkyldithiophosphate (zinc, phosphorus and sulphur) it could contain. Maxima then boosts protection through a proprietary mix of performance additives. The end result is a motorcycle oil that doesn't break down under extreme heat and is tough enough to cushion meshing gears.
Q: WHICH FOUR-STROKE RACING OIL SHOULD I USE?
A: If the bottle of oil doesn't list that it is an API SG Service Category or JASO MA spec, it's not good enough for your motocross bike. Although a bottle of oil might say "motorcycle specific" or "safe in wet clutches," the best endorsement is the API SG or JASO MA designation. It's better to be safe than sorry.
Finally the best answer your can get
http://www.motorexuk.com/info/jaso.htmlIn many 4-stroke motorbikes, the motor oil lubricates the transmission and clutch as well as the engine. If a car grade motor oil is used clutch slipping may occur at high power loads. But if you see the JASO MA specification on the oil container, you can be sure that the clutch will always bite.
Motorcycle engines place different demands on motor oils than do passenger vehicles. In the case of passenger vehicles, the focus is on fuel economy and extended oil change intervals, factors that by the nature of things are not important with motorcycles. On bikes, engines offering increasingly higher torques and R.P.Ms are being used to generate more and more power. And this is where oil additives are causing the wet clutches used on bikes to slip.
JASO MA Offers an answer
In response to the requests from leading motorcycle manufacturers, the Japanese Auto mobile Standards Organisation (JASO) has introduced JASO MA and MB, the first specifications to apply solely to motor oils for 4-stroke motorcycle with wet clutches. These standards set additional lubricant requirements beyond the spark-ignition motor oil grades defined by API or ACEA.
The JASO T 903 bench test determines coefficients of friction under various operating conditions compared with the reference oil. The results allow oils to be divided into two categories:
MA = Non Slipping Oil
MB = Slipping Oil
Coefficient of friction measurements that conform to MA requirements guarantee that clutch slipping will not occur under any load condition on even the most high performance racing bikes. These values are therefore specified by leading motorcycle manufacturers...."
from
http://www2.petrobras.com.br/produto.../perguntas.htmThe additive levels recommended for four-cycle motorcycles are generally characteristic of oils with API SF or SG performance. API SH, SJ and SL oils have an additive level that could be detrimental to the running of the motorcycle gear system, which is also lubricated by the engine oil.
Can I use car engine oil in my motorbike then ?
http://www.carbibles.com/engineoil_bible.htmlQ. Can I use car engine oil in my motorbike then?
A. No you can't.
Well, actually you can in some cases. The real answer to this question lies in the type of motorbike you own. If you own a Bike with a wet clutch (ie. where the clutch sits partially submerged in the sump oil) and you dump car oil into it, all sorts of nasty things happen. Oils formulated for car engines have friction-modifiers in them. When the engine oil gets into the clutch, the friction-modifiers get to work and you'll end up with a clutch that won't bite. Bike oils generally don't have friction-modifiers, so they don't have this problem. If you're not sure, check for a JASO MA spec on the bottle. If you see that on the label, then it means the oil has been tested and confirmed to work with a wet clutch. ......"
Summary
According to the latest JASO documentation available here - Latest JASO Documentation (
http://http://jalos.or.jp/onfile/pdf/4T_EV0604.pdf)
The API ratings are primarily meant for "gasoline engines " and really more applicable to cars etc than bikes. This has been known for a long time . But the manufacturers always mention both API and JASO ratings since these take on different amount of significance in different markets . Finally I was able to find definitive proof that API ratings need not be taken into consideration at all . At the most it can be regarded as the least important factor in deciding engine oils for your motorbike .
The above PDF file explains the same in a very lucid manner . Pls download it and go through Page 8 , section 3.4
So the only ratings we have to consider to be extremely important are JASO MA and the Viscosity index.
API rating is usually for car oils . The ratings are given once in about 3 years or so . Each new rating refers to improvement over the previous version . Ex - SL is better than SG and SM better than SL and SG etc. but what you have to note is that these are ratings for engine oils to be used in passenger cars . (the API website refers to passenger car engines as automotive engines - just look at the spec chart . Ratings for motorbike engine oils is not given by API but still , that std is followed even for motorbike engines in the USA . JASO is the body which gives specific oil ratings for motor bike engine oils.)
No matter what the API rating is , Unless a given grade of oil is rated as JASO MA , or unless the manufacturer claims that it is JASO MA certified , do no use it in your Bike since JASO MA is the only standard rating in the world to be referred to when you use engine oils in your 4 stroke motorbike engines which have a wet clutch multi-plate set-up.
Do not use JASO MB - it is for low friction engines and it is not for use in our bikes . Check the manual of your motorbike - the recommended engine oil is always JASO MA and not MB.
Thus , passenger car oils are not suitable for motorbikes in most cases . There are very rare cases where you a API rated oil which might be rated as SL but still meets JASO MA ratings.