With a diesel 4x4 engine the most common mods are performance chips and exhaust systems.
Fitting a performance chip to the newer diesel engines will usually give a good increase in power, to get the most out of them it's best to get an exhaust system to suit with it, this increase performance on to the diesel engine greatly when combined with an aftermarket chip.
These can alter the fuel consumption to a point that may even give better fuel economy than stock standard settings. The chip basically bypasses the current CPU (stock computer chip) feeding the engine with a different program altering the power output.
Most of these are “plug and play” with simple instructions. Most can also be uninstalled/ installed in your own garage/car port or even on the track if there should be a problem.
Some brands offer up to a staggering 50% performance increase combine with an exhaust package.
Exhaust systems are usually the first mod focused on when it comes to a diesel 4x4 engine.
These modifications will increase torque, power and economy from between 5-20%. Exhaust pipes will generally be bigger (2.5inch to 3inch) in diameter to increase the flow.
A straight through exhaust pipe would be the best however by law every road vehicle must be fitted with a catalytic converter, these help prevent pollution.
The down side of a catalytic converter is reduced fuel economy, to overcome this problem after market catalytic converters have been made, these will help the exhaust system archive more torque, power and economy.
TD or turbo on a diesel 4x4 engine are quite common in the newer model vehicles.
Adding a turbo is a great way to increase torque and power without out increasing much more weight. What they don't do is increase low end torque as the turbo doesn't kick in until at least 1000-1500 rpm, however diesel engines have great low end torque as it is anyway so it really is only a problem with petrol engines.
Turbo's can be upgraded or added to most diesel 4x4 engines depending on what model
and how old the engine is, in this case it would be best to speak to a diesel
mechanic about what the best options are.
Turbo charges work by compression air and forcing it into the engine, fuel and air equal fire, more air (or compressed air) will allow more fuel to be burnt equalling more power.
The turbo spins by using the engines exhaust fumes/gases to spin the turbine creating the compressed air, which is then forced in to the engine at the right rpm (usually from 1000-2000 rpm on a diesel engine) and will give the diesel engine a good boost in power.
Injecting the right amount of LPG gas into a diesel engine can increase fuel economy by about 10%. This is because most diesel engines will not burn all of its fuel, roughly about 10% of the fuel escapes through the exhaust without burning, which means there is 10% power and fuel economy escaping.
The injected gas ensures that this diesel is used by helping it burn.
That 10% wasted diesel will add up over time so a system like this will pay for itself in the long run. However this setup requires the vehicle to be fitted with a LPG tank.