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Page created: 25 Dec 2001; last updated 16 Dec 2002

HOW ENGINES WORK

Before spending any money on additives, one should first try to understand how engines work, then the purpose of the engine lubricating oil becomes obvious.

There are two types of engines: 2-stroke and 4-stroke.   The design principle and operational principle vary and hence the lubrication needs are somewhat different, hence the presence of "2T" and "4T" oils on the market:

(1)    Fuel-oil-air mixture for combustion in 2-stroke engines:

In 2-stroke engines, the crankshaft also doubles as the pressurisation chamber and provides the vacuum force needed to suck/push the fuel-air into combustion chamber, the crankshaft cannot have oil in it for lubrication. Therefore the oil is mixed into the fuel.

On most 2-stroke bikes, the 2T oil is stored in a separate tank from your fuel and automatically metered into your fuel by a mixer/pump, and has to be topped up all the time.

Interestingly in India and Bangladesh, this is not practiced because at the fuel stations, there is a separate pump available where the petrol is already premixed with 2T oil - hopefully in the correct ratio! (Pumps for cars do not have oil pre-mixed in)

(also see "How Stuff Works": http://www.howstuffworks.com/two-stroke.htm )

Frankly, so long as there is oil to lubricate the crankshaft and prevent seizing and damage, any brand of 2T oil would do.

(4-stroke engines do not need this oil as the crankshaft is completely separated from the fuel intake system).

(2)    Engine Oil

For the rest of the 2-stroke engine that is completely separated from the fuel system. Here regular engine oil or "4T" is used. (All cars have 4-stroke engines, so engine oils for cars are obviously "4T"... likewise 4-stroke motorcycles).

(also see "How Stuff Works": http://www.howstuffworks.com/engine.htm )

Most any brand-name 4T oil will do.

One should note that most 4T oils are not just the base lubricant, but are usually blended with the necessary additives. Especially with synthetic engine oils, the additives can be as much as 25 to 35% of the overall content.

If additives were so good, why weren't only additives used and the base oil chucked out? That's because beyond a certain point, the performance begins to degrade again. And in any case, with use, all lubricating components will eventually fail and need to be replaced, hence your oil change.

Brands like Motor-up and other "hey, instant pour-in super performance oil additive" companies play on the misconception that "more is better". They sucker others to buy and use their additives at significant premiums.

If you are wondering why for synthetic oils the replacement cycle time is shorter for motorcycles (5000 km) than for cars (20000 to 50000 km), you must first understand the function of engine oil:

• (a) LUBRICANT: The engine oil works like a lubricant between the sliding surfaces, so that a sliding movement is enabled. The effectiveness of the lubricant is effecive when the gap between the surfaces is narrowed, there is a high enough running speed and the lubricant is of sufficient viscosity. Lubricant is constantly circulated and forms a film over the moving surfaces which is constantly refreshed through internal nozzles and the sump pump. When the oil ceases to be effective, the sliding surfaces tear through the film and damage the metal parts.

• (b) COOLANT: The oil also serves to cool the hot moving parts. Pistons in more highly stressed sport -, turbo or multi-valve engines are cooled by transferring heat directly to the oil, afterwhich the head is released by an additional oil cooler or is transferred to the air or other coolant, e.g. water.

• (c) TRANSPORT OF DEBRIS AND OTHER CONTAMINANTS: On its way, the oil carries and washes foreign matter from the engine into the filter. However the filter can only hold back larger particles. Smaller particles like soot particles (which is unavoidably produced) remain in suspension, and the oil helps to keep them from lumping together to form deposits or "engine mud". Other acid byproducts of combustion and possibly contamination from water must be taken up and neutralised. Modern lubricants therefore have a combination of additives that also fight corrosion and other aggressive reactions.

Also look at the difference in behaviour of the engine: cars typically operate nominally around 2500 rpm, max 5000 rpm while motorcycles operate nominally around 4000 rpm and up to 12000 rpm. The shearing forces between moving surfaces will degrade the performance of the same oil in motorcycle engines far more rapidly than it would in car engines, hence the shorter replacement cycle.

(For those who can read German, Aral german petroleum products company has a very informative website at http://www.aral.de )

Given that in any case you must replace your oil to remove the suspended and disssolved debris, as well as replace it with fresh oil in order to maintain the lubricating film strength, you are better off doing one or two things:

• - use a mineral oil (e.g. "regular" 4T), but replace frequently (typically 1500-2500 km)
• - use a more expensive synthetic (e.g. "Mobil 1", "Esso Ultron") or semi-synthetic oil (e.g. "Mobil XHP" or "Mobil Diesel XHP") and have it replaced less frequently (typically up to 5000 km for synthetic, 3000-3500 km for semi synthetic)
  • synthetic oils have beter characteristicsimprove the performance by extending the life and improving the strength of the lubricating film
  • semi-synthetic oil are mineral oils blended/fortified with synthetic oil to improve their characteristics

Regardless of whether it is mineral, synthetic or blended/semi-synthetic engine oil, the lifespan still remains finite/limited and must eventually be replaced;

Also remember to replace your oil filters regularly, after 6000-10000 km .

There is a distinct difference between engine oils for cars and motorcycles! 

The main problem is that in cars, there is a separate chamber for the engine and the clutch.  In the engine, regular automotive engine oils are used and the purpose of the oil here is to provide maximum lubrication.  In the clutch, transmission fluid is used.

However in motorcycles, a common sump is used so the same oil that lubricates the engine is also used to lubricate the wet clutch.  This means that if the lubrication is so good, the clutch will slip and not be able to engage the final drive properly.  So bike oils must not be too lubricating! (paradox)

Furthermore, the running speed of motorcycle engines is significantly higher.  Cars engines typically run at 0 to 5000 rpm but motorcycles go up to 12000 rpm!  The shearing forces usually break down the engine oil faster than they would in cars.  Also if bike oils are less lubricating than car oils, then the friction is marginally higher than in cars and also leads to earlier degradation.   (dilemma)

Therefore the primary differences in engine oil characteristics for motorcycles are:

• No friction modifiers as that could lead to clutch slippage
• Different proportions of additives:
  • More phosphorous and zinc compounds for enhanced wear protection at high engine speeds and high loads
  • Different dispersant/detergent mix/compounds for better
    high-temperature performance and engine cleanliness

Here is what Mobil says about engine oils for motorcycles (source URL: http://www.mobil1.com/motorcycle/index.jsp)

• Q: Can I use Mobil 1 15W-50 in my bike, just like I use in my car? Mobil 1 is Mobil 1, right?
  
  • A: Mobil 1 for cars and Mobil 1 for motorcycles are markedly different.  Every oil is a balance of benefits.  Mobil 1 Tri-Synthetic(tm) Formula for cars has been developed specifically to satisfy car manufacturers' needs for increased fuel economy and low emissions.  That's why new cars come with friction-modified, low-phosphorus 5W-30 motor oil.  The low viscosity and the friction modifiers help fuel economy.  The low phosphorus levels help protect catalytic converters.

• Q:  So how is Mobil 1 for passenger cars different from Mobil 1 for motorcycles?
  
  • A:  First, let's be clear about Mobil 1's overall benefits compared to those of conventional motor oils, whether for passenger cars or motorcycles:
    *    Superior long-term engine protection.
    *    Superior high-temperature stability.
    *    Excellent low-temperature starting.
    *    Outstanding engine performance.
    *    Low volatility/low oil consumption.
    
    It's a little hard to generalize about the difference between Mobil 1 passenger-car motor oils and Mobil 1 motorcycle oils.  That's because not all viscosities of Mobil 1 passenger-car oils have the same levels of zinc and phosphorus, and there are even greater differences among the three Mobil 1 motorcycle oils.  In general, Mobil 1 motorcycle oils have:
    *    Different base stock systems.
    *    Different additive packages.
    *    Different formulations to meet very specific engine requirements.

• Q:  What are the overall advantages of Mobil 1 motorcycle oils?
  
  • A: In addition to the overall benefits listed above - specifically, high-temperature stability and low volatility/low oil consumption - Mobil 1 synthetic motorcycle oils also offer superior anti-corrosion performance compared to conventional motor oil, which is important in many parts of the country [USA] where bikes may sit in garages for several months of the year.
    
    Compared to conventional oils, Mobil 1 motorcycle oils have superior wear protection, engine cleanliness, high-temperature protection and lower oil consumption performance.
    
    Once you get past these general advantages, you have to deal with each specific motorcycle oil one at a time to understand the benefits.

• Q:  Okay. Let's start with Mobil 1 MX4T. What does it offer that Mobil 1 for cars doesn't?
  
  • A: Mobil 1 MX4T is designed for sport bikes.   Most of these bikes have multi-cylinder/multi-valve engines and use a common sump, which means the engine oil lubricates the engine, transmission and wet clutch.   So unlike Mobil 1 for cars, Mobil 1 MX4T has no friction modifiers, which could lead to clutch slippage.
    
    The motorcycle oil also has more phosphorus/zinc for enhanced wear protection at high engine speeds and high loads.  Remember, most bikes don't have catalytic converters, so higher levels of phosphorus are not a problem. [Phosphorus "poisons"  or ruins catalytic convertors]
    
    In addition, Mobil 1 MX4T uses different dispersant/detergent technology for better high-temperature performance and engine cleanliness.  Mobil 1 MX4T is also offered in a different viscosity grade than Mobil 1 for passenger cars.

• Q:  What about Mobil 1 V-Twin oil? How is that different from Mobil 1 for passenger cars?
  
  • A: Mobil 1 V-Twin oil is designed for air-cooled, large-displacement bikes.  Because of their design, these engines can generate very high localized oil temperatures and high overall bulk-oil temperatures.
    
    As you know, a typical air-cooled V-twin's rear cylinder gets a lot hotter than the front cylinder - it's a matter of airflow.  When it's hot out and you're stuck in traffic, the oil temperature in your bike climbs rapidly.  Above about 250° F, conventional motor oil is going to break down. Mobil 1 V-Twin synthetic oil is good to above 300° F.
    
    In addition, Mobil 1 V-Twin 20W-50 is a higher-viscosity grade than Mobil 1 15W-50 for passenger cars.  And Mobil 1 V-Twin has no viscosity index improvers, so the oil is very "shear stable."  Simply put, Mobil 1 V-Twin synthetic oil won't break down as readily as conventional oil.
    
    Like Mobil 1 MX4T, Mobil 1 V-Twin has high levels of phosphorus/zinc and the same high-temperature detergent technology for superior wear protection and engine cleanliness, even at elevated oil temperatures.
    
    With Mobil 1 V-Twin oil, you can go the full length of the manufacturer's recommended oil change intervals with ease.

• Q: The owner's manual says I should change the oil every 5,000 miles or once a year. I change my oil every 2,500 miles or twice a year. So why do I need that kind of protection?
  
  • A:  For peace of mind and added protection. You pay a lot for a bike these days, so why risk running your engine in ordinary oil? Just like Mobil 1 synthetic oil for cars, Mobil 1 synthetic motorcycle oil helps keep your engine clean - free from varnish and deposits - and smooth running mile after mile, no matter what conditions you ride in.
    
    Mobil 1 benefits engine life and performance. In fact, the lubrication capability of Mobil 1 motorcycle oil helps maintain peak horsepower and acceleration throughout the life of your engine. And with Mobil 1 you can go the full 5,000 miles between oil changes.
    
    So, if you want to ride your bike long and hard and not be concerned about the oil, choose Mobil 1 motorcycle oil.

So, what is good for cars is not necessarily good for bikes.   By the same token, engine oil additives that might do well in cars may not be good for bikes.  Especially since most of the additives claim to reduce friction better than engine oil, this could have significant impact on the wet clutch of your motorcycle.

So how to know which oils are good for your bike.  Besides the usual API classifications (the newer oils will usually meet API SG and SH standards), there are two classifications by the Japan Automobile Standards Organisation specifically for motorcycles which address the issue of clutch slippage.  The standards are JASO MA and MB (MB standard is higher than MA). 

So check the markings on the bottle of oil you purchase (presumable of reputable brands and from reputable sources, of course).  Motorcycle oils usually have a symbol or icon of a motorcycle marked on the bottle.  If you are not sure, check the ratings on the bottle: as long as the oil you buy meets the JASO MB and MB standards, you should not have any worry about.

Also, don't use oil which is too thin or too thick (oil viscosity is defined by SAE into various weights where smaller number means thin and bigger number means thick; multigrade oils are indicated by W, where the number preceeding the W indicates the viscosity when cold and the number following W is the viscosity when hot).   Typically for most bikes, SAE 10W40 will be adequate.  V-twin cruisers are better off with a heavier one like that goes up to SAE 50 (e.g. 20W50).   Besides being absurdly expensive and not good value for money, 0W and 5W is really too thin and will not leave much lubricant lying about on the parts during cold start..

If your oil is getting worn out, simply replace with it fresh oil, any oil... it doesn't have to be synthetic or mineral or what have you.

Remember, oil is the life-blood of your engine while petrol is the fuel. Lose that life-blood and your engine is well dead.

Gasoline fuels and engine oils sold by the major petrochemical companies (e.g. Esso, Mobil, Shell, etc.) is adequate to serve the needs of most of the motoring public.

Before buying, check whether your oil is suitable for motorcycles or not.  They should meet the JASO MA standards.

To use to fuel additives or oil additives is merely a waste of money!  The companies selling these products not only charge a enormous premiums, they claim performance improvements that may be temporary or worse, there may be detrimental effects on your engine.

Replace your engine oils and all other lubricants regularly according to manufacturer recommendations.

No oil, bad oil or worn-out oil = bike death.

-FIN-

Following complaints, the Bureau of Consumer Protection of the US Federal Trade Commission investigated a number of these products and their manufacturers and marketeers have been taken to task.

These include the "Motor-Up" that keeps being advertised in Singapore and Malaysia by the mail-order companies... read it yourself from the official US Government websites!

-----

FTC free consumer education brochure, "Gas Saving Products."
http://www.ftc.gov/bcp/conline/pubs/autos/gasave.htm

-----

Other FTC developments

These are only the tip of the iceberg... does not include those who market outside the USA under different brand names.

• DuraLube & Motor-Up - to Pay $2 Million in Consumer Redress
  http://www.ftc.gov/opa/1999/9904/motorup5.htm
  http://www.ftc.gov/opa/1999/9905/duralub2.htm
  http://www.ftc.gov/opa/2000/03/motor.htm
  
• Slick50 - $10 Million in Redress to Consumers
  http://www.ftc.gov/opa/1996/9607/slick.htm
  http://www.ftc.gov/opa/1997/9707/slick.htm

• STP Corporation - TO PAY $888,000 CIVIL PENALTY
  http://www.ftc.gov/opa/1995/9512/stp.htm
  
• VALVOLINE "TM8" engine treatment
  http://www.ftc.gov/opa/1997/9710/valve.htm

• Prolong Super Lubricants "ETC" product
  http://www.ftc.gov/opa/1999/9909/prolong.htm

• Speedway "zMax" product
  http://www.ftc.gov/opa/2001/02/zmax1.htm