Engine Oil – IS THE BRAND REALLY IMPORTANT?

The question “what brand of oil” keeps coming…… but what REALLY matters is the grade.

Unless you are considering using budget off the shelf oil from your local supermarket, the brand is far less important than making sure you are using the right grade and specification.
Well known manufacturers such as Castrol, Penrite, Mobil and Shell all make very high quality lubricants suitable for everything from 50cc mopeds to 200 hp+ superbikes.

True or False……

1 The most expensive oil is the best. FALSE

2 You can use a different grade as long as its top quality oil. FALSE

3 You can’t use synthetic oil in older engines. FALSE

4 You can’t switch from mineral to synthetic oil in the same engine. FALSE

5 Semi-Synthetic oil is just as good as full synthetic oil. FALSE

Engine Oil – The Right Grade For Your Engine

Specified Engine Oil Grades for Piaggio, Vespa, Aprilia & Moto Guzzi

All Scooter 2T engines

2T Synthetic ISO‐L‐EGD

Piaggio & Vespa 150cc 4 valve iget engines.

0W‐30 Full Synthetic (all 4 valve iget engines with Start/Stop)

All Piaggio 350cc engines.

15W‐50 Full Synthetic (Beverly BV350 / X10 350)

All other scooter 4 stroke engines

5W‐40 Full Synthetic (125‐150 2V / 3V and 250 / 300 / 400 / 500 4 valve)

Aprilia V‐Twin engines

15W‐50 Full Synthetic JASO MA/MA2

Aprilia V4 engines

5W‐40 Full Synthetic JASO MA/MA2 (Except RSV4 1100)

Aprilia RSV4 1100 Factory

10W‐50 Full Synthetic JASO MA/MA2

All Moto Guzzi V-Twin engines

10W‐60 Full Synthetic

Piaggio 350 Engine

Piaggio’s newest engine - the 350 is packed with a host of great features including:

·         4 valve head with roller cam followers.

·         Shim valve clearance adjustment.

·         Dry crankcase lubrication system with reed valve scavenge.

·         Coaxial coolant and oil pump drive.

·         Wet multi-plate centrifugal clutch.

The design of the 350 engine is all about performance and efficiency and provides equivalent output to the 400cc master engine with better fuel economy and lower emissions than the 300cc Quasar.

The 350 is only 60cc larger than the existing 300 but develops 50% more power!

Servicing:

Service intervals for the 350 are 10,000 km as per most of the Piaggio Vespa range however 15W – 50 engine oil is specified rather than the usual 5W – 40.

Full synthetic engine oil is specified as per usual. Oil volume for the 350 is 1500 ml.

80W – 90 gear oil to API GL4 is specified for the reduction gearbox (rear hub) which also lubricates the multi-plate clutch housed inside the newly designed rear hub.  Hub oil volume is 500 ml.

Valve clearance adjustment is via interchangeable shims which sit directly on top of the valve stems and are accessed by removing a snap-in control block which allows the rockers to be moved sideways for ease of access.

The 350 engine is currently available in the Beverley 350 & X10 350 models.  It's likely that this engine will eventually be used in other models such as the Yourban.  It's unlikely to be fitted to the Vespa frame however as the 350 is possibly too powerful for that frame and suspension format.

 Piaggio 350 Engine – Technical Specifications

Engine: Single-cylinder 4-stroke.

Engine capacity: 330 cm³.
Bore x Stroke: 78 mm x 69 mm.
Timing: 4-valve single overhead camshaft with roller rockers.
Cooling: Liquid.
Lubrication: Dry Crankcase.
Starter: Electric.
Gearbox: Speed CVT with torque server.
Clutch: Automatic centrifugal multi-disc oil bath.
Emissions: Euro 3.

Engine Knock - "Detonation Danger"

Detonation, also called knocking, pinging or pinking occurs in petrol engines when one or more pockets of the air-fuel mixture explodes (detonates) in an uncontrolled manner within the combustion chamber but outside the normal zone of combustion.  The normal combustion process should grow progressively from the point of ignition (the spark plug) and burn all the available fuel so that maximum power and efficiency is gained from the fuel-air charge and peak cylinder pressure is reached at the optimum part of the cycle, generally a few degrees after the piston has reached the top of the compression stroke.

Detonations create shock waves within the combustion chamber that are heard as the characteristic metallic "pinging" sound and cause the cylinder pressure to increase dramatically and at the wrong part of the cycle.  Allowed to continue, detonation or “engine knock” will cause serious long-term damage to the engine and even catastrophic failure.

The smaller more regular detonations can erode the surface of the piston and cylinder head, wearing away metal fragments which end up in the oil causing damage to other components.  The larger more violent ones can rupture the combustion chamber by breaking sections of the pistons away and punching holes right through pistons or the cylinder head itself.

The main causes of detonation are:

1.         Using fuel with too low an octane rating for the engine.  Octane is the index of a fuel’s resistance to detonation (see previous articles on fuel)

2.         Fuel-air mixture too lean causing higher combustion chamber temperature.

3.         Ignition timing overly advanced.

4.         Excessive engine load caused by incorrect gear selection or throttle opening too high for current engine speed.

Detonation can (and should) be avoided by:

1.         Using fuel with the correct or higher octane rating.

2.         Ensuring that fuel mixture is correct – i.e. correct carburettor or injection system settings.  (Richer air-fuel ratio will help limit detonation).

3.         Ensuring that ignition settings are correct.

4.         Correct gear selection allowing engine to operate in the optimum range and not be lugged under load in higher gears.

Engine design is also important in terms of the proclivity for detonation.  Factors such as compression ratio, the amount of turbulence generated in the combustion chamber during induction and compression, the shape of the combustion chamber and position of the spark plug are some of the factors which are considered.  These factors are generally outside the control of vehicle owners however and in most cases the problem can be avoided by considering points 1.& 4. In the above causes and strategies for avoidance.

The images below show some of the damage detonation can cause -

Premium – Regular & the Octane Story Part 3

Following on from part 2 of “Premium – Regular and the Octane Story, this section will discuss ethanol in fuel.

Gasoline blended with ethanol is now available in many countries, most notably Brazil where the minimum ethanol content in all fuel is 25%.  In most other parts of the world using ethanol blends is still a choice although it’s not always made clear whether some fuels are blended or not.

In the majority of cases, modern fuel injected European bikes and scooters are able to run on ethanol blended fuel but at a volume of no more than 10% (E10).  In some cases ratios higher than this (more ethanol) are approved by some manufacturers however this should be confirmed for your particular bike or scooter before using fuel above 10% ethanol.

Whatever the environmental and/or strategic advantages or disadvantages there are in the use of ethanol blended fuel, from a technical point of view there are no advantages at all unless an engine has been specifically designed to use it.

While blending with ethanol effectively increases the octane rating of standard gasoline, it also decreases the over-all energy content.  Performance and fuel economy are therefore also decreased.  An ethanol blended fuel with an octane rating of 98 will return lower performance and fuel economy than an unblended premium gasoline with an octane rating of 98.

The following points should be considered with regard to ethanol blended fuel:

1.     The energy content of pure ethanol is around 20 MJ/l (Megajoules per Litre) compared to straight gasoline which has about 34 MJ/l .  This means that ethanol produces over 30% less energy per unit than gasoline and therefore will give lower performance than gasoline when compared in the same engine.

2.     Total fuel consumption is higher when using ethanol blended fuel compared to gasoline in the same engine due to the reason given in point 1 above.

3.     Ethanol has a higher octane rating than regular or standard gasoline however engines can only take advantage of this if they are designed or modified to suit.

4.     Ethanol is hygroscopic which means that it will absorb moisture from air which contaminates the fuel and can then cause phase separation meaning that the ethanol can split off from the gasoline, evaporate at a different rate thereby seriously compromising the remaining fuel.

5.     Over time ethanol can attack and corrode fuel system components including plastics and aluminium and can also cause fuel system blockage.  For this reason and the one in point 4 above, use of ethanol blends is particularly unsuited to bikes and scooters as they often sit for long periods between use.

Premium – Regular & the Octane Story Part 2

Following on from Premium – Regular & the Octane Story Part 1 where the importance of using the right grade of fuel were explained, it’s also important to understand that there are differences in fuel formulas and how fuel grades are identified, depending on where they are sold.

There are two things to consider that are far more important than names such as Premium, Ultimate, Power, Super,  etc.  The first is the octane rating and the second is whether or not the fuel is blended with ethanol.  In this article we will deal with specifically octane ratings and how you can determine exactly which grades of fuel sold in your county are suitable for your bike or scooter.

There are two main scales used to rate fuel octane.  The most commonly used is the RON scale.  RON stands for Research Octane Number.  The test used for this scale is best suited to rate fuel used in normal road vehicles.

The other rating scale is the MON scale which stands for Motor Octane Number.  This scale is used in motor sport and aviation and is specifically designed to rate fuel for engine conditions at higher loads.

In most cases, commercially available fuel has been rated for both these scales by the testing agency and the MON will be typically 8 - 12 points lower than the RON rating.  It is not possible to reliably convert between the two scales as commercial fuels differ widely and the difference in the rated number will be higher or lower depending in the actual fuel formula.

The important thing for bike and scooter owners is knowing what octane rating is recommended for their bike or scooter and which scale has been used to specify it.  The next thing is then to match that with the fuel available in your country.

Most countries use the RON scale to specify the octane rating of fuel sold at commercial outlets.  These include all of Europe, the UK, Ireland, the Middle East, South Africa, Asia, Australia , New Zealand, most South American and some Central American countries.  In these countries 95 Octane fuel for example is 95 RON if not already specified at the outlet.

In some other parts of the world the rating system and display at the outlet is quite different however.  Canada, the USA, Mexico, Brazil, and possibly some other Central and South American countries use an average of the RON and MON which they call the AKI and which stands for “Anti Knock Index”.  At some outlets in these countries it is labelled on pumps as (R+M)/2 or by another designation POM which stands for “Pump Octane Number”.  This causes a lot of confusion for owners in these countries and also for readers of on-line forums when they are getting what seems to be contradictory “advice” from other owners about what fuel to use.

The Italian manufacturers are careful to specify the grade of fuel required and this will be detailed in the Owner’s Manuals or other technical documentation.  Fuel ratings will be in RON as this is the European standard however in some cases both RON (sometimes written NORM) and MON (sometimes written NOMM) ratings are given.  Bikes and scooters specifically for the US and Canadian market may also have fuel recommendations listed in the documentation by the (R+M)/2 method as is used in their area.

The table below shows a comparison between RON, MON and AKI with examples of some fuels in different markets.  There are however regional variations in a lot of countries so it is always best to find out the actual octane rating of the fuel you are buying rather than rely on the description.   Ratings for the reference compounds n-heptane and iso-octane as well as straight ethanol and methanol are also shown for general interest.

FUEL	RON	MON	AKI
Standard Unleaded – Europe, UK, Ireland, RSA	95	85
High Octane Premium Unleaded – Europe, UK, Ireland	102 - 97	88
Standard Unleaded  - USA, CDN	91 - 92	82	87
High Octane Premium Unleaded - USA, CDN	98 - 97	88	94
Standard Unleaded  - AUS, NZL, RSA, Asia, Mid East	91 - 92	82
Premium Unleaded  - AUS, NZL, RSA, Asia, Mid East	95	85
High Octane Premium Unleaded - AUS, NZL, RSA, Asia, Mid East	100 - 97	88
n-Heptane	0	0	0
Iso-Octane	100	100	100
Ethanol	108	90
Methanol	109	89

Premium - Regular & the Octane Story Part 1

There is a lot of confusion (particularly on the on-line forums) about grades of fuel and what grade is right for any particular bike or scooter and why.  The following will help to dispel some of the myths about fuel.

FACT 1:

In a few limited cases, using premium grade fuel can improve the performance of your bike or scooter but in most cases it does not.

FACT 2:

In all cases where an engine is designed to run on premium grade fuel, premium fuel should be used as running on lower grade fuel can potentially damage the engine.

FACT 3:

Premium fuels do not necessarily produce more motive power than standard fuels and in some cases when compared in the same engine actually produce less.

FACT 4:

The formulas used in premium fuels are designed to decrease their activation energy so that they ignite less easily and burn in a slower, more controlled manner.

Described variously as Gasoline, Petrol, Benzin, Benzina etc. - depending on where it is sold, motor fuel is made up of organic compounds distilled from crude oil.  The main difference between “Premium” or “Super” grades and what is variously referred to as “Standard”, “Regular” or “Normal” is the octane rating.  Premium fuels have a higher octane rating than standard fuels which means they burn in a more controlled manner and do not as is commonly believed, produce more power.

“Octane” is not (as is commonly believed), some kind of performance additive.  Octanes are in fact a family of hydrocarbons that are present in gasoline and one member of this family, Iso-Octane is used as a measurement benchmark of a fuel’s ability to withstand compression without pre-ignition or detonation which is the cause of the phenomenon known as “engine knock”.  This “detonation” which can usually be is heard as a pinging or knocking sound when the engine is under load is caused by the fuel pre-igniting and exploding in the cylinder rather than burning and expanding in a controlled manner.  Detonation will immediately cause the engine to become inefficient and if allowed to continue will cause major damage, even to the point of melting pistons or breaking connecting rods.

The octane rating of fuel is tested using a specially calibrated laboratory engine to measure the fuel’s performance relative to two of the hydrocarbon compounds, n-heptane which has very low resistance to detonation and iso-octane which has high resistance.  The measurement is calibrated so that an octane rating of zero would be equal to a fuel made up of 100% n-heptane and an octane rating of 100 would equal a fuel made up of 100% iso-octane. 

This does not mean that 100 octane gasoline is pure iso-octane.  It is not.  It is made up of many compounds that when combined, give it that rating and this is why some types of fuel have ratings above 100.

The thing that determines which fuel is right for your bike or scooter’s engine is the actual design of the engine itself and primarily its compression ratio which is the measure of how much the air / fuel mixture is squeezed or “compressed” in the combustion chamber as the mixture ignites.  A range of other factors are also relevant such as the combustion chamber shape, method of fuel delivery (Carburettor or EFI) ignition system design, the type of cooling system and in the case of EFI engines, the software design and level of engine management sophistication.

A more highly tuned engine with a high compression ratio will be more efficient and produce more power, however it will need fuel with a higher octane rating to achieve this without detonation occurring.  While it seems contradictory that some high octane fuels actually have lower energy content by volume and burn less easily than standard gasoline, highly tuned engines need this more stable type fuel to develop maximum power.

So the choice is simple.  Use whatever grade of fuel the manufacturer specifies as this is what the engine is designed for.  Using higher octane fuel will cost more and in almost all cases will not improve performance of your scooter or bike.  Using lower octane fuel than is specified may save you money in the short term but will in all likelihood damage the engine.