P Type
Tires

P Type Tires (225/60/14)

The PType Mk2 uses a 14x7 wheel, so it has a small yet wide tire.  Unfortunately, not many tires are available in this size.  A few high performance tires were available during the '80s and early-mid 90s, but their production has ceased.  Below is a listing of the OEM tires as well as the tires that are currently available. 
Original Equipment Tires
The Bridgestone Potenza 137V was one of two factory tires delivered on all US-spec P-Type 1982-1986 Celica Supras.  It is HR speed rated and has a treadwear rating of 140AA.   They have been discontinued since 1989. 
The Dunlop SP Sport D3 was the other OEM tire.
The Pirelli P6 (VR speed rating) tire was standard on European market P-Type Celica Supras.
Some early prototype Celica Supras were photographed with Yokohama 352's and Pirelli P7's.   None of the production cars wore these tires.

Available Tires

Make/Model Price UTQG Speed M+S? Website
Sumitomo HTR4 $52 320AA H Yes www.tirerack.com/tires/sumitomo/su_htr4.htm
Michelin Pilot XGT H4 $88 400AA H Yes www.tirerack.com/tires/michelin/mi_pilotxgth4.jsp
Falken ZE502    ZIEX $55 420AA H Yes http://www.vulcantire.com/ze502_6_t.htm
B.F. Goodrich Radial TA $50 400AB T Yes www.tirerack.com/tires/bfg/bf_radta.htm
Dunlop GT Qualifier $50 440AB S Yes www.tirerack.com/tires/dunlop/du_gtqtr.htm
Yokohama Avid S/T $60 340AA T Yes http://www.yokohamatire.com/04b1c.html
Kelly Charger $50 400AB T? Yes  

Discontinued Tires

Make/Model Price UTQG Speed M+S?

Website

Yokohama A509 $75 160AA H No  
Yokohama AVS Intermediate $130 160AA H, V No  
Yokohama AVS U+4 ? ? H Yes  
Falken FK06U $70 360AA H Yes  
B.F. Goodrich Comp TA HR4 1st Gen $45 400AB T, H Yes  
Bridgestone Potenza 137V $85 140AA H No  
Bridgestone Potenza HP41 $75 ? H ?  
Michelin EPX Sport ? 250AB S Yes  
Goodyear Eagle GT+4 $55 ? H, V Yes  
Dunlop SP Sport D3 $45 ? H No