Abstract
It is investigated that the soak conditions have an effect on the amount of N2O in exhaust of gasoline vehicles at starting. As a result, it is found that the amount of N2O increases by the effect of the short time soak. Next, by the factual survey of the vehicle usage condition, it is found that the vehicles less than 2 hours soak is more than 40 % of the whole business vehicles. With these results, it is indicated that the operation of the short time soak test is necessary for the evaluation of the green-house-gas emission.
