PASSENGER CAR MOTOR OIL TRENDS

 

PASSENGER CAR MOTOR OIL TRENDS

 

Gulf Global Technology Manager, Dr Y P Rao offers an insight into the latest

developments in Passenger Car Motor Oils and shows how Gulf has responded

 

The technical requirements for passenger car motor oils (PCMOs) are undergoing rapid changes. These are governed by the two main specification bodies in the USA and Europe, the API and ACEA, respectively. In the USA, the car OEMs have so far been following the API specifications for oils but this situation may change in future considering the GM’s recent initiative of licensing oils against their trade mark “dexos”.

 

In Europe the OEMs use the ACEA specifications, but most of them have their own additional in-house requirements. In Japan the OEMs also have in-house requirements for their own ‘genuine part oil’ brands as well as following the performance profiles set by ILSAC for gasoline engine oils and by JASO for light duty passenger car diesel engine oils. In this article we review the trends and the implications for oils, in particular the Gulf products.

 

PCMOs: Key Technical Drivers The Global PCMO specifications are affected by three major drivers: ever more stringent emission norms, improvement in

fuel economy requirements and increased durability of engines, exhaust after-treatment systems including compatibility with bio-fuels and operation under severe conditions.

 

The impact of these three key drivers on European PCMOs is discussed below.

 

1. Emissions: Compatibility with exhaust after treatment systems (catalysts), has led to lower limits for SAPS in the ACEA Oil Sequences and new OEM specifications. The latest Euro 5 emission norms will result in the increased demand for such oils, identified by the ACEA C Oil Sequences, for both initial as well as service fill.

 

2. Fuel Economy: Demand for increased fuel efficient engine oils is driven by the simple need to reduce CO2 emissions, through reduced fuel consumption, as well as a lower cost of ownership. This in turn will lead to increased use of low viscosity oils, such as 0W-30 and 5W-30 grades, as well as oils with lower HTHS viscosity.

 

3. Durability: The demand for increased oil drain interval to match longer mechanical service intervals is driven by the need to reduce waste oil generation and lowering the cost of ownership. Taking these demands together, the modern engine oils are required to function under severe operating conditions imposed by new engine designs, new exhaust after-treatment systems and even new types of fuels (e.g., bio-diesel). The new engine oil technology is required to lubricate the latest engines for longer periods under severe operating conditions while retaining/improving the equipment life. Much the same trends are present in the USA, with emphasis is on the following factors:

 

o    Improvements in fuel economy, and fuel economy retention to meet new CAFE targets

 

o   Engine oil robustness to ensure that there is no detrimental performance with flexi-fuel vehicles (operating on gasolinealcohol mixtures up to E85)

o   Protection of emission control systems to retain the exhaust gas conversion effi ciency throughout the intervals between services.

 

Convergence of these three drivers had led to the periodic upgrading of the PCMO specifications, as discussed below. PCMO specifications and Gulf Oil’s actions to meet current and future requirements:

 

European Specifications – the ACEA Oil Sequences to meet the latest passenger car and light duty truck engine oil requirements, ACEA revised all A/B and C engine oil sequences (along with E sequences of heavy duty diesel engine oils) in March 2009, the details of which were published in Orange Disc No. 19. This ACEA 2008 revision represented the biggest performance upgrade since the introduction of the ACEA Sequences and the major changes are given below.

 

o   Sludge Limits were increased to provide protection against higher power densities, turbo-charging, direct injection, and fuel quality issues.

 

o   Piston Cleanliness requirements (VW TDI Test Limits) were increased to raise engine oil durability, to cater for the use of bio-fuels, increased fuel dilution levels from DPF regeneration, and to ensure all engine oils are suitable for use in direct injection diesel engines.

 

o   TBN Limits were introduced in ACEA A/B sequences to ensure the durability of engine oils used in areas where the fuel quality is poor, and where ACEA C type oils would be unsuitable. Conversely, the cars that require ACEA C Sequence oils should not be lubricated with ACEA A or B type oils.