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Motor vehicles are seldom used in ambient conditions like those defined in current emission regulations. For example, most of the year average temperatures across Europe fall much below the range of legislative testing. Furthermore, it has been widely demonstrated that cold-starts at low ambient temperature increase the emissions. Therefore, there is a growing need to broaden the range of legislative emissions tests and set a separate low-ambient test with respective emission standards. This paper gives emissions test results form a joint research programme between Sweden and Finland. Altogether 11 late model gasoline-fueled TWC vehicles were tested at ambient temperatures of +22 and -7 °C using a variety of different driving cycles. Apart from the driving schedule, other test parameters like vehicle preconditioning, manual vs. automatic transmission and the effect of external cooling were studied and discussed.

The introduction of the three way catalyst (TWC) has considerably reduced emissions from gasoline fueled cars. Most of the pollutants from these cars are emitted during the cold start period. At lower ambient temperatures (below +20°C), as in the Northern part of Europe, these emissions increase considerably. In Sweden engine block heaters, mostly in combination with compartment heaters, are often used to increase the driver's comfort. The increased engine temperature also reduces emissions. Block heaters are also suitable for after-market installations, and can thus reduce emissions from in-use cars. This paper reports the investigations of the effects of a block heater on emissions and fuel consumption. It was decided to conduct tests on three types of light duty vehicles: cars with TWC, cars without TWC, and one car with very low emissions (i.e. TLEV). The cars were tested according to the FTP-75 test procedure at +22, +5 and -15°C ambient temperature.

Alternative-fuelled vehicles are a growing market, and emission performance of these vehicles should be thoroughly investigated. The emission legislation is however very diversified in different countries; a short summary of the legislation in the EU, the USA and Brazil is presented in this study. In the EU regulations, everything measured with the FID (Flame Ionization Detector) is treated as hydrocarbon emissions. In the USA the alcohols and aldehydes are measured and reported separately from hydrocarbons. In Brazil, the alcohol part can be measured separately on voluntary basis. The influence of some of these differences has been further investigated in this report. Results from two related studies are presented. The FID response for ethanol was investigated and emission testing of an E85-fuelled FFV (Flex Fuel Vehicle) was performed.