Um, truck spares are real tires, usually the same kind of tire as the rest of the truck but mounted on an unpretty steel rim. I know that'* how my S10 and Avalanche spares were. Nothing about them was meant to be "temporary" except the steel rim looking like crap compared to the other rimgs.
The only spares I know of that are supposed to be temporary are the mini donut spares that come with cars. This is only talking about the tire too, not the rim.
Also, that crap that spares say "Do not exceed 55 MPH" is a load of crap. Most spares are rated up to 80 MPH, they're just covering their asses with that stuff.
2004 Chevy Silverado Z71 - 15% tint, FTDRL, All-on-high, 5000k lows/fogs, tinted tails, color matched grille, Sound by Kenwood.