[kouki_s14]

i've been reading forum after forum and thread after thread about oil
and i've come to the conclusion that i should either run 10w40 or 15w50 in the summer heat for my RB. i cant seem to decide which to run since i plan on stocking up for the spring/summer/fall heat.
when i go to the track this summer i will run the thicker 15w50 unless you guys think it's a bad idea. but is 10w40 sufficient for daily driven or should i go with the 15w50? im stumped, help please...

thanks
henry