The Tata Nano comes with the smallest petrol engine in the mass production cars in India. The engine is a 624 cc unit, making out 37.5 BHP and 51 NM of torque. The figures sound small for a car but the total weight of the car has also been significantly kept as low as possible. The engine does not have any problem at 30,000 kms as the only reason for the problem can be due to improper servicing or late servicing of the vehicle. The engines are highly tested before launching a car and the Nano's engine can easily reach 80,000 kms without showing any problem in terms of performance and noises. You can get your car checked at an authorized Tata service center and inquire about the tips to keep the engine safe and clean for a longer period of time.