It’s well known that dirty drives are better than cleans in nearly every application. I have numbers to back that somehwere, but I’m too lazy to find them right now, so you’ll have to take my word for it.
In short, the heat generated by your thrusters is negligible, at best, and your ships efficiency is heavily dependent on your power plant’s stats. An A rated plant, even an overcharged one, shouldn’t cause you an issue on anything typically used as an explorer.
I’ve done testing in open space, as well as above a high-G world, in this case, Achenar 3.
Using a hot guardian powerplant, and grade 5 dirty drives on my T6, I was unable to overheat my ship, unless I was performing intentionally erratic maneuvers— something that is not advisable when landing on a planet like this. You can achieve the same result with cleans and intentionally erratic flying.
My PvP-spec Diamondback Scout was also used as a testbed for difference in temperature between the drive types and plants while silent-running was engaged.
I found that boosting didn’t have as much of an effect on heat as I expected, and each mod is very much tied to general thruster activity. Clean drives would allow me to sit stationary in silent running for a considerable amount of time over dirty, however there wasn’t a big difference between actual combat maneuvering.
As mentioned previously in this thread, cleans will increase your base idle temperature by a small amount, both in regular space and supercruise, due to their higher power draw. You will not see any benefit to clean drives while in Supercruise, only a slight negative, as there is no thruster activity like there is in normal space. That is nothing more than a placebo effect, same as the sense of increased supercruise maneuverability after drive mods.
While both dirty and clean make you faster, the gain in performance you get with dirty over clean far outweighs any benefits you would get with clean drives.
Not that big of a deal you can even do completely without a PD, but if you struggle with the rocket spamming skimmers, then every little bit helps.
It felt like the PD where not doing anything, but when I got back into the ship both, even the one on the far side, have each used up ca. 3000 of their ammo. So not sure what went wrong then.