Ceramic coated pistons (tops) allow the heat generated by the combustion to not be 'soaked' into the aluminum...lengthening the life of the piston (most pistons fail from fatigue...caused from heat cycling the material)..less heat soaked into the surrounding materials leaves more energy to go to the turbine wheel...

we also routinely DFL coat piston skirts for reduced friction in the cyl bore.

you don't ceramic coat rods...you can shot peen them for a modicum of additional strength (do a google on 'stress risers' in metal)...but we have DFL coated rods (dry film lubricant...think "Teflon"...oil dispersing/shedding coating)...as any oil that clings to the rod (or anything else that is rotating) will affect the engine balance.< though not an issue on most diesels...with low-ish operating rpm.


ceramic coating the turbos...is actually ceramic coating the turbine housing...reflects the heat away from the cast iron housing...leaves more energy to be put into turning the turbine wheel.

There are many types of coatings...and you shouldn't expect to pick up more than a few percent in power output from just the coatings alone...all other things being equal. Most guys do it for cosmetic reasons...external on headers, external on turbine housings, etc...to make a real gain, the coating should be inside these components.

but..a few percent (3-5% might be realistic)..on 1000hp might make the difference in winning/losing...or not fracturing a piston sooner than you might have...