The Fiero spare tire size is still being made in the 15" size as 125/70 R15 by Kuhmo. Not sure if it is made in 14" size and that may be hard to find. The 14" tire is no longer used but on some classic cars. Although Fiero spares were hardly if ever used and most still remain un-used; 30+ years of just sitting and possibly deteriorating is something to consider. I'd keep it inflated to spec and try to use it in an emergency (at low speed) but if it will last is a big question.
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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "