... is in the large-scale machinery, ships or large cars used by domestic and foreign oil Have clearly defined ... small city has about 20,000 small cars and 30,000 large cars around.Calculation:Oil for one small car ... (including oil and gear oil)Oil for one lager cars per month, about 15 kg (including oil and gear ... * 20,000 = 100,000 kg = 100 tonsMonthly large cars produce waste oil 15 kg * 30,000 = 450,000 ...