There are different components in a vehicle which can be modified to increase the efficiency of the engine. Only do your homework in understanding and studying the different things you can do to boost the strength and efficiency of the engines.
In freeing up strength you need friction. Using roller tappet camshaft, roller rocker arms, dual roller timing system, needle-bearing cam sprocket, low tension piston rings, higher piston-to-cylinder wall clearances (within limits), higher bearing clearances, higher clearance valve, and winding tray can achieve this.
You would need to make sure that the temperature of a tire and the wheel size are both indicators of a sluggish engine. The bigger your engine’s contact patch is, the more power it needs to transfer. Tire inflation must hold to ambient temperature. Temperature has a pronounced heat effect.
Another part of an engine that can increase good efficiency if care is taken of the velocity stack. A velocity stack refers to a trumpet-shaped structure which is mounted on the air inlet of an engine system which improves airflow. This particular item eliminates the induction of turbulence, so you can get horsepower.
You may need to calculate your fuel line properly, in addition to boosting your engine horsepower. Do not forget the most important friend, torque, of horsepower. It is the dual-plane manifold supplying a torque and high ceilings to horsepower.
And if you want more power and improved engine performance a decent cylinder head swap and cummins parts will be of great help. You will also be required to have a camshaft profile to work well with your cylinder heads.
There is also a turbocharger and supercharger, on demand now. Check out and read Pure Power Diesel‘s infographic to learn the difference between the two and their advantages and disadvantages in improving engine efficiency.