BKR5E-11 versus BKR6E-11 spark plug question

[registering]

Howdy all,
I currently run NGK plugs Mazda partno 0000-18-BP03 (NGK. BKR6E-11), however from what I've read I should be running Mazda partno 0000-18-BP01 (NGK. BKR5E-11). I run a fairly stock engine (intake+exhaust) at 87 octane, but I run it at the track so it gets lots of high-RPM day-long use. Any reason to NOT run the BKR6E-11? Those are what Mazda said was recommended for my 2002.5 P5. I'm in south Florida, so high temps and high humidity down here. The original plugs had some carbon buildup and white-ish tips after 33,000 miles (not surprising), but they were Denso K16PR-U 11 (I guess Mazda swapped brands??).
Thanks for any tips!

 

[kcbhiw]

The BKR6E-11 is just a step colder than the BKR5E-11's. Being in FL and your description of your 5 series plugs, I don't foresee a problem with the 6's.

 

[registering]

Okay, I'm swapping out my plugs (wires are still within spec) and plan to just go with the 6Es unless anyone sees a reason to go with the hotter 5Es. I've attached a picture of one of my plugs after about 22,000 miles. I guess the hotter plug wouldn't have such white tips?

 

[igdrasil]

If you using 87 and pushing the car, 6e its a good choice.

 

[registering]

Yeah, I'm going to more and more track days, so it's spending more and more time in the high RPMs, but the plugs seem to look good, so I'll stick with the 6Es, thanks.