Last time I pulled the top end of my engine off, it was filthy. Inside the Lower Intake Manifold, back of the throttle plate and IAC passage, inside the Supercharger.....always carboned up.

This time I opened it up and it was SPOTLESS after 50k HARD miles. Anyone care to take a guess as to why?

Top Engine clean.... or u towed it the 50k miles

Hrm, i assume your EGR is running. Good Synthetic oil keeps insides clean...

Top engine cleaner? Either that or you're always going WOT so nothing has a chance to stick, or go backwards.

Not oil related cleanliness, and no top end cleaner ever in my car. But you're thinking along the right lines.....sortof.

I have something unique on my car.

A HomeMade Beer Injection System???

Even closer, John

Oh duh, water injection. Kills carbon with one fell spray!

EDIT: i should spritz some water in mine sometime, and see how it goes.. But i don't wanna knock the world loose either, and clog my cat, until i can afford to swap it.

Water/Alcohol injection

Water - alchohol injection ?

You got it. That'* the FINAL answer. Clean as a whistle. Works like a charm. And I don't run it very often either.

Great old-school trick for this was spraying water into the carb of a running engine with the downpipe disconnected. Most cars would blow chunks of carbon out the back. This usually became necessary after carbon deposits caused deiseling after shutoff on a carb'ed car. FI cars don't have the deiseling effect, as the fuel is entirely shut off, but still suffer from carbon buildup over time.

Water Injection has many benefits, this being a big one of them.