Not exactly, heat causes KR for the most part, theory is colder tstats reduce KR but unless your tuned for the colder stat is worthless because the car will just use more fuel. Also I dont belive it helps reduce KR. The thing is the M90 basically turns into an oven and post blower air temps are high which causes most KR aside from restrictive exhaust not letting the engine breath.
Sent from the Milky Way