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The reduction of CO2 emissions is one of the most important challenges for the automotive industry to contribute to address global warming. Reducing friction of internal combustion engines (ICEs) is one effective countermeasure to realize this objective. The improvement of engine oil can contribute to reduce fuel consumption by reducing friction between engine parts. Electrification of ICE powertrains increases the overall efficiency of powertrains and reduces the average engine oil temperature during vehicle operation, due to intermittent engine operation. An effective way of reducing engine friction is to lower the viscosity of the engine oil in the low to medium temperature range. This can be accomplished while maintaining viscosity at high temperatures by reducing the base oil viscosity and increasing the viscosity modifier (VM) content to raise the viscosity index (so-called “flat viscosity” concept).

In this research, we investigated the improvement of combustion and anti-knocking properties as factors that affect the lean limit in order to reflect in fuel design. First, as a basic study, characteristics such as the Laminar burning velocity and Ignition energy of hydrocarbons, which are highly effective in improving combustion speed, were examined. In addition, using the knowledge obtained in the basic study, several concept fuels were created by blending the blend- stocks of the refinery aiming to meet or exceed the current standards in Japan. Their lean limits, thermal efficiencies, and effects on CO2 emission were investigated.

Thermal efficiency can be improved with a super lean-burn. In a super lean-burn engine, combustion takes place at lower temperatures, meaning lower energy losses and much greater thermal efficiency. In Part I (presented at PF&L 2019) [1], we studied the effects of various fuels on the lean limit in super lean-burn conditions. We found that the lean limit could be greatly extended and thermal efficiency improved with the right combination of engine technology and fuel technology. We also found that the lean limit closely linked to the duration from start-of-spark discharge to CA10, and that substances which shorten this duration extends the lean limit. In this study, we evaluated the effects of hydrocarbons closer in composition to commercial gasoline on the lean limit and found that at the specific components, the lean limit could be much higher than that with commercial gasoline. We also studied the lean limit extension mechanism by focusing on autoignition.

A gasoline particulate filter (GPF) is installed in a passenger vehicle for new exhaust regulation. However, ash in gasoline engine oil has a risk of clogging as well as performance decrease in the GPF. Therefore, new gasoline engine oil whose ash contents decrease to 0.8 mass% was developed in order to avoid the GPF clogging. In addition to this, our developed oil improves fuel efficiency (+0.2% from our SN 0W-16 fuel eco type oil) as well as anti-wear performance for gasoline engine, which resulted in meeting API SP/ILSAC GF-6 0W-16 official certification.

Breath alcohol interlock systems are used in Europe and the U.S. for drunk driving offenders, and a certain effect has been revealed in the prevention of drunk driving. Nevertheless, problems remain to be solved with commercialized detectors, i.e., a person taking the breath alcohol test must strongly expire to the alcohol detector through a mouthpiece for every test, more over the determination of the breath alcohol concentration requires more than 5 seconds. The goal of this research is to develop a device that functions suitable and unobtrusive enough as the interlock system. For this purpose, a new alcohol detector, which does not require a long and hard blowing to the detector through a mouthpiece, has been investigated. In this paper, as a tool available on board, a contact free alcohol detector for the prevention of drunk driving has been developed.