Well, first off, as you know ceramic coating makes a massive difference and second a lot of people aren't worried about the minor effects of a bump of a couple degrees while cruising. Most people who even think to ask this question are worried the most about changes in temp during acceleration... and coming off the line from idle the temp difference is pretty big.

So did you buy it ceramic coated, or is this something you ve done later on?

It is a big diffrence between SHOW cars and GO cars. Myself I am preparing my car with the GO factor Firsth in mind. But of course I like a clean shining engine compartment. Not enough to loose 1 sec on 1/4 mile thow. And that is why I have asked this, because in competition you stay with the engine runing and wait for your turn to go. The engine heats up, and if you have a alumimium pipe from the intercooler to the combustion chamber, your cooled-from-the-intercooler air heats right back...
By the time you race along... for the 20 sec. max down the track... Your pipes don't have the time to cool back.
get my point?
And this is why I have asked this. I was thinking that the metal is treated somehow, but I wasn't sure. Are all this aluminum pipes ceramic coated, or just some? Does the seller specifies if they are ceramic coated or not?

Your requirements are precisely the reason I push for people to differentiate between "my intake stays cool after a long drive" and "my intake hasn't even cooled after a quarter mile".

Some companies offer a choice of uncoated or coated, most don't even offer it. Don't presume that what you've got is coated though. It may come from the factory with a clear coat, but that does nothing for temps. Ceramic coating is typically rather inexpensive though.

Ceramic helps, but nothing beats an insulated sleeve.