Tests on a large number of cars prove that you can save as much as 6% by tuning your car regularly. If your engine emits black smoke, has poor pulling power or consumes large quantities of oil, get it checked immediately at a reputed garage. A delay, may prove more expensive in terms of petrol and oil as compared to the cost of an overhaul.
Use of bi-metallic spark plugs saves over 1.5% fuel and reduces exhaust emissions too. Get your car serviced at every 5000 kms.