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• Delivering Quality

• 5.1 Vehicle Emission Standards
• 5.2 Fuel Quality and Emissions
  • 5.2.1 Effects of Petrol Composition and Properties On Vehicle Emissions
  • 5.2.2 Correlations between Petrol Quality and Emissions
  • 5.2.3 Effects of Diesel Composition and Properties on Vehicle Emissions
• 5.3 International Fuel Specifications
  • 5.3.1 Japan
    • Petrol
    • Diesel
    • Relevance to New Zealand
  • 5.3.2 Australia
    • Relevance to New Zealand
  • 5.3.3 European Fuel Specifications
    • Relevance to New Zealand
  • 5.3.4 World-Wide Fuel Charter
    • Relevance to New Zealand
  • 5.3.5 United States of America
    • Petrol
    • Diesel
    • Relevance to New Zealand

This section discusses vehicle emission standards and the relationships between fuel quality and vehicle emissions. It then reviews the current fuel quality specifications used internationally and discusses their relevance to New Zealand. Specifications for individual properties of petrol and diesel are compared and discussed in more detail in Sections 7 and 8 respectively.

In recent years, changes to fuel quality specifications in the USA, Europe, Japan, Australia and elsewhere have been largely driven by air quality targets which in turn have led to regulated vehicle emission limits and, more recently, fuel efficiency requirements. Vehicle technology and fuel specifications have been developing in response to these requirements. The relationship between these key drivers is illustrated in Figure 5.1.

Figure 5.1: Drivers for Fuel Quality

5.1 Vehicle Emission Standards

The first controls on vehicle exhaust emissions were introduced in the USA and Japan in the 1960s, in response to concerns about the impact of increased vehicle use on urban air quality. Since then, legislators in all the world's main vehicle markets have developed tailpipe and evaporative emission standards and set progressively more stringent limits on regulated emissions, such as CO, NOx, hydrocarbons, visible smoke and particulates.

Emission standards prescribe limits for the regulated exhaust components as well as the test conditions and test procedures under which these limits apply. These standards define test cycles to be used for engine and vehicle certification that are intended to simulate a range of, and reflect the transient nature of, actual vehicle operating conditions. Performance requirements relating to durability are now also stipulated. As noted, these standards have driven the development of engine and emissions control technology and also fuel quality specifications.

In practice, these test cycles can be quite different to actual driving cycles, so that even for the most sophisticated test cycle, actual on-road emissions may differ significantly from those derived from test cycles. In addition, the different vehicle manufacturing countries have developed their own standards and associated test cycles, in response to the nature of their own particular air quality problems and through dialogue with their own manufacturers, so that direct comparisons between countries cannot easily be made.

New Zealand currently has no mandatory vehicle emission standards and is somewhat unusual in this regard. However, new vehicles coming into New Zealand have generally been designed and equipped to meet the requirements of their main markets. Therefore the current New Zealand vehicle fleet incorporates a wide range of engine and emission control technology spanning the whole history of vehicle emission limits. Until now, fuel quality has not been a limiting factor in the performance of this technology but this is now changing.

5.2 Fuel Quality and Emissions

A number of overseas studies have been undertaken on fuel specifications in recent years. The US Auto/Oil Quality Improvement Research Programme (AQIRP) was initiated in 1989 and completed in 1997. The programme, established by 14 oil companies and three domestic car manufacturers, identified clear relationships between fuel specifications and emissions for petrol vehicles. A similar study in Europe, the European Auto/Oil Programme (EPEFE), initiated by the European Commission in 1994, looked at the effect of specific fuel characteristics on emissions from both diesel and petrol vehicles. The objective of both programmes was to provide data to assist legislators and policy makers in developing and assessing measures to reduce emissions and improve air quality. The key findings from these studies in relation to both petrol and diesel, are summarised below. More detailed descriptions of the programmes are given in the Environment Australia review of fuel quality (EA, 2000a).

5.2.1 Effects of Petrol Composition and Properties On Vehicle Emissions

• Sulphur content affects the performance and durability of catalysts. Advanced catalyst formulations being developed for Euro 4 compliance are particularly sensitive and can only be used with very low sulphur fuel (50 ppm or lower).
• Fuel parameters such as volatility and aromatics content affect engine emissions as follows, but do not directly affect emissions control technology.
• Reducing the volatility of petrol through reduced Reid Vapour Pressure (RVP) and/or lower distillation temperatures, has a significant impact on VOC emissions.
• Addition of oxygenates reduces CO emissions.
• Reduction of aromatics content reduces emissions of air toxics, hydrocarbons and CO.
• Reduction of olefins significantly reduces butadiene emissions.

There is a down side however; some of these changes may affect the energy content of the fuel and so increase fuel consumption.

5.2.2 Correlations between Petrol Quality and Emissions

Various correlations have been developed for predicting toxic and other emissions as a function of fuel quality, based on the results of the AQIRP, EPEFE and other studies. These are generally expressed as mass emission rates of individual components per kilometre, and presented as functions of fuel composition or other properties. It is important to note that the data on which these correlations are based is generated from vehicle emissions testing and standard drive cycles and may not be particularly representative of actual driving conditions. The Ministry of Transport's VFECS work has identified that driving patterns and congestion have a major impact on actual emission rates.

While the emission rates for vehicles fitted with catalytic converters have generally been expressed as functions of multiple fuel quality variables, the data for older vehicles without catalytic converters have been presented as percentage changes to individual parameters in isolation and, it is noted, the results were not always clear cut.

The computer models developed using the correlations are designed to predict vehicle emissions (tailpipe and evaporative) and do not predict the resultant air quality. However, they do provide a good basis for comparing the likely effects of changes to certain fuel parameters.

The goal of the United States' Environmental Protection Agency's (USEPA) reformulated gasoline (RFG) programme has been to achieve vehicle emissions reductions relative to 1990 levels (refer Section 5.3.5). The USEPA has developed a complex model based on fuel quality/emissions relationships to provide a means of measuring these reductions through fuel quality changes, while allowing some flexibility for refiners as to how they achieve this through control of fuel properties. Fuel characteristics modelled include sulphur, benzene, olefin, total aromatics and oxygenate content, as well as distillation parameters and RVP. The USEPA model considers both evaporative and exhaust emissions and generates an Air Toxics Index (ATI) as well as emission rates for benzene, aldehydes, butadienes and polyaromatic matter.

The South Australia EPA has recently (March 2001) incorporated the USEPA model into its environmental protection legislation (SAGG, 2001).

The air toxics model approach has been used in the past as a basis for setting specifications using pool averages and caps rather than fixed limits for certain petrol parameters. The use of this approach in New Zealand is discussed in Section 9.6.1 but is not proposed as part of this review, for the reasons outlined therein.

5.2.3 Effects of Diesel Composition and Properties on Vehicle Emissions

There is a clear correlation between some diesel properties and regulated emissions, but drawing general conclusions is somewhat difficult due to such factors as inter-correlation of different fuel properties, different engine technologies or engine test cycles.

• Sulphur increases particulate emissions in both light duty and heavy duty diesels. It also degrades the performance of nearly all emissions control equipment. In particular, de-NO_x catalysts and continuously regenerating particulate traps require very low sulphur levels.
• In heavy duty diesels engines, increasing cetane number reduces HC, CO and NO_x emissions. Reducing fuel density reduces NO_x and PM but increases HC and CO emissions.
• Light duty diesels show different fuel sensitivity to heavy duty diesels.

The characteristics of light and heavy duty diesel engines are discussed in Appendix C.

5.3 International Fuel Specifications

This section looks at a number of fuel quality specifications currently in existence and their relevance in setting new standards for New Zealand. These are as follows:

These specifications have not developed in isolation but result from ambient air quality and vehicle emission standards in the respective jurisdictions in which they apply, which in turn have developed in response to particular air quality problems. The Review has not considered those air quality standards or emission standards in any detail.

Comparisons of these international specifications for petrol and diesel with the current New Zealand specifications is made on a property-by-property basis in Sections 7 and 8 respectively.

5.3.1 Japan

Petrol

The current Japanese standard for motor gasoline (petrol), JIS K2202:1999, includes mandatory limits on sulphur (100 ppm max.), benzene (1% max. by volume) and MTBE (7% max. by volume). Prior to January 2000, the benzene limit was 5% max. by volume There are currently no limits on aromatics or olefins. Two grades of petrol are specified in the standard, No.1 (96 RON min.) and No.2 (89 RON min.). Petrol must not contain methanol, lead or kerosene.

Diesel

The Japanese standard for diesel fuel for diesel engines (primarily for automotive use) is JIS K2204:1997. Prior to 1992, the allowable sulphur content of diesel was 2000 ppm. This was reduced to 500 ppm in 1997. A recent high profile court case over health impacts from vehicle emissions has prompted the Japanese Environment Agency to push ahead with plans to reduce allowable sulphur levels to a maximum of 50 ppm by the end of 2004. Five cold weather classes are specified, according to pour point.

Relevance to New Zealand

• Japanese vehicles dominate the new vehicle market.
• Used vehicles imported from Japan (both petrol and diesel driven) make up a significant proportion of the New Zealand vehicle fleet. These vehicles were designed to run on fuels domestically available in Japan and to meet Japanese emission levels.
• Tighter controls proposed on diesel vehicle emissions within the next 3- 4 years may increase the availability of second-hand older technology vehicles for export.

5.3.2 Australia

In the past, Australia has had no national mandatory controls governing fuel quality. Fuel properties affecting performance, health and environmental impacts have variously been regulated at state and national level. However, Australia has had vehicle emission standards for a number of years. Exhaust and evaporative emission standards for new petrol driven cars and light commercial vehicles are currently set by ADR 37/01, revised in 1997/1998. ADR 70/00, implemented in 1995/1996, sets emission limits for heavy-duty diesel vehicles.

The Australian Government has recently finalised national environmental standards for petrol and diesel quality. These standards will be implemented as regulations under the National Fuel Quality Standards with the initial changes coming into effect from 1 January 2002. The process and outcomes of the Australian review are summarised in various references (EA, 2000a, b, c; EA 2001a, b).

The standards focus primarily on air quality i.e. those fuel parameters with health and environmental implications. In summary, they harmonise:

• Petrol standards with Euro 2 in 2002 and Euro 3 in 2005;
• Diesel standards with Euro 2 in 2002 and Euro 3 in 2006 (except for sulphur in diesel which harmonises with Euro 4 in 2006).

Where standards are already better than these, they have been locked in and some flexibility has been allowed in the transitional period (2002 - 2006). A number of Australian states already regulate environmental parameters such as vapour pressure in petrol and diesel in sulphur, with more stringent requirements and/or a tighter timetable for implementation than the new national regulations. As previously noted, South Australia has recently regulated some aspects of petrol quality using an air toxics model.

The national proposals also allow for development of operability standards for petrol and diesel which focus more on fuel performance requirements and these are currently under development for intended implementation alongside the environmental standards in 2002. Proposals had not been published at the time of writing.

Relevance to New Zealand

• Australia is a significant source of imported fuels and petrol blendstocks for New Zealand, and also a significant source of vehicles.
• Australia has opted to harmonise substantially with European standards but on its own timetable.
• The Environment Australia review was guided by a number of principles to assist in determining the extent of harmonisation with European standards and the timeframe that was most appropriate for Australia, and many of these have been taken into consideration in the New Zealand Review.
• Australia is our nearest neighbour and competitive issues in terms of transport costs may be relevant.

5.3.3 European Fuel Specifications

The current European fuel specifications have developed out of European Union directives on vehicle emissions, starting with passenger cars in 1992, and subsequently extending to heavy duty vehicles and light commercial vehicles by 1997. These emission standards became known as Euro 1 and Euro 2. The drive for further emissions reduction has since led to the Euro 3 emission standard (implemented in January 2000), a tighter Euro 4 standard (from 2005, applicable to all vehicles) and a Euro 5 standard for heavy duty vehicles from 2008.

In developing these standards, the relationship between emissions and fuel quality was recognised and has resulted in the development of European-wide specifications for diesel and unleaded petrol. The current European standards for fuel are EN 228:2000 and EN 590:2000 respectively, which reflect the parameters required to achieve the Euro 3 emission targets. They cover environmental, health and driveability requirements. While these apply equally to all member countries of the European Union, they also allow for volatility specifications (for petrol) and cold flow properties (for diesel) to be set on a national basis. These fuel specifications are referred to as Euro 3 elsewhere in this document.

In order to meet Euro 4 emissions standards in 2005, the corresponding Euro 4 fuel specifications include further reductions in sulphur and aromatics content of petrol, and lower sulphur limits for diesel. Some European countries, notably the United Kingdom and Sweden, have brought forward the availability of lower sulphur fuels by means of tax incentives. All diesel now sold in the United Kingdom is ULSD (ultra-low sulphur diesel, maximum 50 ppm) and ULSP (ultra-low sulphur petrol) is now also widely available.

Following completion of the second stage of the Auto/Oil programme (Auto/Oil II), the European Commission is currently proposing a progressive phase-in of sulphur-free (<10 ppm) petrol and diesel from 2005 to 2011.

Relevance to New Zealand

• European standards are effectively a true international standard with respect to international harmonisation of fuel quality, as unlike national standards, they apply across national borders.
• They incorporate environmental, health and operability parameters, and are therefore a good model for what could be included in our specifications.
• Australia is working towards alignment with Euro 3 and eventually Euro 4, and is a significant source of imported fuels and blendstocks, hence alignment with European standards by New Zealand over time would complement regional alignment.
• New Zealand imports vehicles from Europe which has some of the leading technology in light duty diesels (France in particular) and is a significant manufacturer of heavy duty diesels used here.
• European fuel standards have been developed to achieve emissions standards which address urban air quality issues particular to Europe - these issues are not all necessarily relevant to the New Zealand situation.

5.3.4 World-Wide Fuel Charter

The World-Wide Fuel Charter (WWFC, 2000) is a set of recommendations for unleaded petrol and diesel specifications, produced by a group of four international automotive manufacturing associations. The purpose was to promote a greater understanding of the fuel quality needs of motor vehicle technologies and to harmonise fuel quality world-wide in accordance with vehicle needs. The original charter was published in 1998 and revised in 2000.

The four associations that were involved in the development of the charter are:

Four categories of specification were developed for diesel and petrol, reflecting different levels of engine and emissions technology required by international vehicle markets.

Table 5.1: World-Wide Fuel Charter Fuel Categories

Although the charter did have some oil company input, it clearly represents the international automotive industry's perspective.

Relevance to New Zealand

• Current New Zealand fuel quality is roughly equivalent to Category 1 or slightly better. Categories 2 and 3 represent possible short and medium term targets respectively, whereas Category 4 is looking beyond vehicle technology currently available.
• The specifications have a slant towards engine and emissions control technology and specify a number of parameters that are probably not necessary in a regulatory specification.
• The specifications largely reflect current and developing technology which forms only a small part of the current New Zealand fleet.

5.3.5 United States of America

Fuel quality in the United States is regulated at both state and federal level. The State of California has the most stringent requirements in the world with respect to vehicle emissions, and as a consequence, fuel quality. Since 1990, the USEPA has been working to implement the use of cleaner fuels on a national basis through the Clean Air Act.

Petrol

In 1995, Phase 1 of the reformulated gasoline (RFG) programme was introduced (RFG1), requiring the use of RFG in key metropolitan areas with major air quality problems, particularly related to ozone. In reformulated gasoline, the components are regulated to achieve cleaner burning and lower vehicle emissions, by imposing limits on, for example, volatility parameters, aromatics and as oxygen content. Phase 2 of the programme (RFG2), requiring more stringent limits, was brought in from January 2000. California has had its own specifications for reformulated gasoline (CaRFG2) and a third phase (CaRFG3) was introduced in September 2000.

The focus of the RFG programme has been on reducing emissions of VOCs, air toxics and NOx in order to achieve emissions targets relative to a 1990 baseline. All RFG produced by refiners is required to be certified, with the emissions performance of the fuel being determined using a complex air toxics model developed by the USEPA. The use of pool averaging allows some flexibility in meeting targets for individual components and properties.

The specification of a minimum oxygen content in petrol as a means of reducing CO emissions, was first introduced under the Clean Air Act in 1990, much earlier than the RFG programme. This legislation effectively made the use of oxygenates mandatory in a limited number of cities with high levels of carbon monoxide.

As a result of this move, MTBE, the most popular oxygenate, has been widely used in the United States for a number of years. However, in response to recent concerns about groundwater contamination, the use of MTBE and other oxygenates (except ethanol) will be banned in California from December 2002. Other states have followed suit.

Diesel

USEPA standards for diesel fuel for on-road use came into effect in 1993. These included a limit of 500 ppm sulphur, a minimum Cetane Number of 46 and total aromatics limit of 35% maximum by volume. Exemptions to the sulphur limit apply in certain states, and there is currently no sulphur limit on diesel for non-road use. In California, more stringent standards were adopted around the same time, with a similar sulphur limit and a 10% maximum by volume limit on total aromatics. The Californian standard applies to both on-road and off-road use, but excludes marine and locomotive use and allows some flexibility for alternative specifications.

In 1999, the USEPA gave notice of its intention to set a more stringent standard for diesel fuel in line with efforts to implement Tier 2 vehicle emission standards. Earlier this year, the Bush administration confirmed its intention to proceed with a further reduction in diesel sulphur levels to 15 ppm from 2006, in conjunction with more stringent controls on emissions control equipment for heavy diesel vehicles.

Relevance to New Zealand

• Californian requirements, being the most stringent in the world, effectively fix the "green" boundary of the fuel quality spectrum, thereby providing a benchmark as to what can actually be achieved given the resources.
• The USA is consequently a leader in vehicle emissions control and fuel efficiency technology.
• New Zealand imports few vehicles from the USA.
• The USA's significant lead over New Zealand in implementation of vehicle emissions control policies provides an opportunity for us to learn from their experiences (viz. MTBE).
• The USEPA air toxics model has recently been adopted in South Australia which is a source of imported petrol for New Zealand.