hi. 86xr600r. i'am running a ngk dpr8ea-9. for climate below 41 deg. F. been useing this the whole time. seems fine. just wondering if it would be benificial to go w/ a plug rated for warmer climate.dpr7ea-9. when i go into town i'am hanging at 65 mph + depending on if someone is on my a** or not for 20 mi. or so. would this rateing for a warmer climate make the engine run cooler? thanks. tim. temp. is around 75-80 F. in summer.