I have the same tires as the video. They fit perfect, like he says.

 

285s will add some weight to the tires, also most people and brands recommend atleast a 9.5 inch wide rim for 285's. Having tires that are too wide for the rim may cause a sloppy feel from what ive read, although that guy in the vid did say they "gripped well" on autocross.

285/40/19 pilot super sports weigh 31 lbs per tire

265/40/19 pilot super sports are 25 lbs per tire.. somewhat significant weight difference of unspung weight

 

One more question... Now if I buy 2 285's for the rear and leave the stock perellis on front, what kind of problems would that cause? or should i just do 4 all around?

 

Come again?