TTI vs Dougs

Underhood temperatures reduced by 100 degrees with the ceramic TTI’s vs similar cars with stock exhaust at summertime car shows. Not scientific, but did use a thermal temp gun.
Really? That was my question. Is heat dissipation. Old saying. "Older headers work better?" Is because oxided steel dissipates heat better. Now im sure today's coatings take heat dissipation into consideration. But all they seem to be concerned about is at what temperature they discolor? My rusty Hookers do a very good job at that.