ok so I guess 245/45/16 is not a common size and there arent too many tires in that size. At least not in the local stores around here.

But you go with 245/50/16, boom there are like 10 plus tires to choose from.
Why so? And can I just go with 245/50/16 ?

 

Hmm... In 245/45-16 size, in max and ultra performance catagories, Tire Rack sells:

Bridgestone Potenza S-03 Pole Position
Dunlop SP Sport 9000
Michelin Pilot Sport
Yokohama AVS Sport
Avon Tech M500
BFGoodrich g-Force T/A KDW
Bridgestone Potenza RE750
Continental ContiSportContact
Dunlop SP Sport 8000
Fuzion ZRi
Goodyear Eagle HP Ultra Plus
Kumho ECSTA Supra 712
Sumitomo HTR Z
Yokohama A008P
Yokohama AVS ES100

 

I think he means there's no Federals or Sears Guardsmans in that uncommon size.