New standards for four stroke motorcycle lubricants

Citation

(1999), "New standards for four stroke motorcycle lubricants", Industrial Lubrication and Tribology, Vol. 51 No. 1. https://doi.org/10.1108/ilt.1999.01851aab.003

New standards for four stroke motorcycle lubricants

New standards for four-stroke motorcycle lubricants

Keywords Four-stroke motorcycle oil, Lubricants, Standards

Issue No. 2 of the 1998 volume of Industrial Lubrication and Tribology featured an article on the subject of lubricants for four-stroke motorcycles, and highlighted a number of problem areas associated with the use of friction modifiers in these applications. The use of friction modifiers, whilst benefiting fuel utilisation efficiency in automobile engine applications, caused problems in certain areas of the drive train and associated components of motorcycles which depended upon a certain degree of controlled friction for satisfactory operation.

To address this problem, preparatory work has been carried out by the motorcycle working group, under the engine oil subcommittee of Japan Automobile Manufacturers Association (JAMA). This included a survey of the existing specifications for four-stroke cycle engine oils and the engine test procedures and reference oils used. This was followed by an evaluation of four-stroke cycle engine oils with actual engine tests. After this preparatory period, the "Motorcycle four-stroke cycle engine oil subcommittee" was set up in April 1996 under the motorcycle technical committee of the JSAE, comprising representatives from academia, motorcycle manufacturers, oil companies and additive suppliers. The subcommittee started by establishing a standard that specifies test procedures to properly evaluate the quality of four-stroke cycle engine oils for motorcycles. This was followed by the definition of a classification standard based on the test procedures. During the standardisation work, existing hardware and evaluation procedures were, as far as possible, incorporated into the standard test procedures. In addition, the principle has been to establish specifications that are suitable for four-stroke cycle motorcycle engine oils currently on the market (or to be developed in the future). The following two draft standards were established and have been circulated to the relevant committees for comment.

JASO T 903-98 motorcycles ­ four-stroke cycle gasoline engine oils

This specifies the general quality levels (in terms of API, ILSAC and ACEA specifications) and general physiochemical properties required. In addition, a "performance classification" is included which differentiates between those oils containing friction modifiers and those without, as determined by the test procedure detailed in the second standard.

JASO T 904-98 Motorcycles ­ Four-stroke cycle gasoline engine oils ­ test procedure for friction property of clutch system

This draft details the test procedure used (an SAE No. 2 clutch friction test machine or equivalent device), the test sample being compared with reference samples of known frictional characteristics.

There is a compelling need for the clarification of proper specifications and classifications relating to such lubricants. Motorcycle sales in the UK are escalating rapidly, with sales figures showing pronounced increases compared with the same period of last year (e.g. 55 per cent increase for May), a large proportion of these being four-stroke machines. In addition, organisations such as the Motor Cycle Industry Association are lobbying Government to recognise the environmental benefits and reduced congestion advantages associated with the use of two-wheeled transport to be taken into account in its forthcoming White Paper on and Integrated Transport Policy. Even in the less developed areas of the world, where two-strokes have historically predominated, environmental pressures are beginning to influence a move towards the use of four-stroke engines.