Search Results

A new 0W-20 gasoline engine oil was developed to improve fuel economy over ILSAC GF-2 5W-20 gasoline engine oils and to meet ILSAC GF-3 requirements. The main improvements made were to viscosity and friction modifiers. Viscosity at 80°C was adjusted to obtain better fuel economy than with 5W-20 oil in the Japanese 10-15 mode test. Therefore, low-temperature viscosity decreased to 0W and high-temperature high-shear viscosity exceeds 2.6 mPa?s. Friction modifiers and other additives were investigated to find the lowest friction characteristics. The resulting formulation shows more than a 2.0% fuel economy gain in the Japanese 10-15 mode test and the new oil has been certified as meeting ILSAC GF-3 requirements.

Fuel dilution is one of the phenomena requiring attention in direct-injection engines. This study examined the factors contributing to increased fuel dilution in direct-injection and conventional multipoint injection gasoline engines, focusing in particular on fuel dilution in the oil pan. The results showed that fuel dilution is affected by fuel consumption, fuel properties and oil/cooling water temperatures in multipoint injection engines. In addition to these factors, fuel injection timing is another factor that increases fuel dilution in direct-injection engines.

To reduce engine exhaust emissions, we have had to deal with this global environmental problem from the fuel side by introducing oxygenated fuels, reducing the RVP and using low aromatics. But when we change the fuel components and distillation, we must take note about how these affect the engine driveability. We have used T50, T90, RVP and so on as the fuel index up to the present. It is possible to characterize the fuel from one aspect, but these indexes don't always represent the real feature of the fuel. In this paper we propose a New Driveability Index (here in after referred to as NDI) that is more realistic and accurate than the other fuel indexes. We used a 1600cc DOHC L4 MPI type engine. We used Model Gasolines and Market Gasolines, see Appendix(1), (2) and (3), and tested them according to the Excess Air Ratio Response Test Method (here in after referred to as λ-R Test) that was suggested in SAE paper #930375, and we calculated the NDI statistically.