A new proposal for those seeking improved performance and fuel efficiency through earth tuning. The earth wire connecting the factory exhaust manifold cover to the vehicle body. Braided wire is used, but conductivity deteriorates over time. By replacing this earth wire with a braided wire similar to the original, but much thicker and more efficient, the flow of electricity is improved. Revive deteriorated earth wires and bring out the original performance of the vehicle. This is maintenance tuning.