CHENNAI Chennai: The price of petrol and diesel in Chennai has remained unchanged for the last 216 days. Accordingly, the price of a litre of petrol is Rs 100.75 and the price of a litre of diesel is Rs 92.34. Accordingly, today the price of a litre of petrol in the city is Rs 100.75 and the price of a litre of diesel is Rs 92.34. Oil companies use the current crude oil price in the global market and the value of the Indian rupee against the US dollar as primary variables to decide the price of petrol and diesel.