FAQs ABOUT AUTOMOBILE AND MOTORCYCLE OIL
The owner’s manual of any automobile/motorcycle outlines the specifications and SAE viscosity classes that lubricants need to meet to be safely used with that vehicle. These specifications are always indicated on lubricant packaging as well.
WHAT IS A SPECIFICATION?
It is an abbreviation that provides guidance on the qualitative characteristics of a lubricant and its designated uses.
Each specification is the result of extensive testing (including motor and laboratory tests) which the lubricant must pass in order to meet certain basic performance requirements.
For more information, see the dedicated automobile and motorcycle lubricants page.
HOW DO I EVALUATE OIL PERFORMANCE?
By correctly reviewing the product specifications, you can get information on and understand the basic quality levels a lubricant meets or exceeds. However, this indication does not specifically tell you by how much a lubricant may exceed the minimum standard. Lubricants that meet the same minimum level are thus often incorrectly considered as qualitatively identical when, in fact, they are not. Some exceed standards more than others.
HOW DO I CHOOSE THE SAE VISCOSITY BEST SUITED TO MY VEHICLE/MOTORCYCLE?
In some cases, the viscosity class is not set by the manufacturer or indicated in the owner’s manual. In this case, the user can choose the viscosity best suited to their engine based on the external temperature and their driving style. The SAE viscosity class of a multi-grade oil is defined by two numbers separated by the letter "W" (stands for ‘winter’).
The initial number relates to the viscosity class measurement at low temperature and the second at high temperature or 100° C.
The higher the number, the greater the viscosity of the lubricant for a given class. Lubricants with a low initial number (meaning more viscosity at lower temperatures) are a better choice when vehicles are used mainly in colder climates. On the other hand, lubricants with a high second number (meaning more viscosity at higher temperatures) are a better choice when vehicles are used for sports driving or where temperatures are higher. In latest generation cars, low viscosities are also indicated to improve fuel economy.
WHEN TOPPING UP OIL, CAN I MIX DIFFERENT LUBRICANTS TOGETHER?
Yes, in emergency situations. Lubricants with similar properties and formulated for the same uses can be mixed together. This is the case even when it comes to mixing mineral and synthetic oil or vice versa. But, you need to consider that final performance after mixing may be different and possibly lower. If you want to avoid this possibility, mixing oils may not be the best solution.
DO DIESEL AUTOMOBILE ENGINES NEED DIFFERENT LUBRICANTS THAN PETROL ENGINES?
Although diesel and petrol engines have different needs, the latest generation lubricants typically meet many of the requirements of both.
CAN I USE AUTOMOBILE ENGINE OIL IN A MOTORCYCLE AND VICE VERSA?
No. Generally, motorcycles that have an integrated gearbox and oil-immersed clutch need specific lubricants that can lubricate the engine and transmission. This assures the efficient transfer of driving force from the engine to the gearbox without excessive slippage between the clutch discs. Regardless of this, bear in mind that motorcycle engines operate at higher speeds and temperatures than automobiles. For this reason, they require a special kind of oil which can work under and support these more stringent conditions.
On the other hand, motorcycle oil may not be suitable to or meet the specific needs of the latest generation automobiles such as those designed for long journeys, fuel economy, vehicles with low saps, etc.
WHAT ARE THE ADVANTAGES OF SYNTHETIC LUBRICANTS?
Synthetic lubricants are formulated with base oils that are not directly derived from petroleum refining. Rather, they are made through an industrial chemical process. Synthetic bases give lubricants superior characteristics in terms of higher fluidity at low temperatures, better resistance to oxidation degradation at higher temperatures and less evaporability (lower oil consumption). A synthetic product may sometimes, but not necessarily, be better than a mineral product. Its actual “value” may be judged based on final performance or referring to various technical assessments.
HOW OFTEN DO I NEED TO CHANGE THE OIL?
The oil change interval is determined by the manufacturer and is indicated by the vehicles' on-board computer or in the owner’s manual. However, the manufacturer also generally indicates a time interval for replacing lubricants. Driving style, type and intensity of use and external environmental conditions can all affect the length of this interval.