Diesel prices fell further in the city—to below the Rs 78-mark on Monday. The price of the fuel was Rs 77.92 per litre in Mumbai. The price of petrol has also been dropping gradually, although it was constant for three days. The price of petrol in Mumbai was Rs 87.86 a litre. Similarly, on Monday the price of petrol and diesel in Thane and Navi Mumbai dropped to Rs 87.99 per litre and Rs 78.04 per litre respectively.