Well, to go beyond what's available from the OEM, you'd need to
replace the turbo and injectors, and you'd probably need to find a
way to improve the cooling, as well. Then you'd have to recalibrate
the ECM.
How does safety and MPG of 4x4 trucks compare with other model trucks?
Safety standards are the same for vehicles classified as trucks.
The miles per gallon rating is less on a 4x4 because it takes more
power and torque to turn all 4 wheels, thus using more fuel.