The spare is still a steel wheel= heavy
You'd be far better off with a set of factory 17" cast aluminum wheels,
I see them on kijiji/fleabay all the time barely used.
They are by far the lightest of the stock wheels at just a hair under 24lbs ea.
Throw a set of 275/50R17 DR's and you're good to go.
Some guys even installed softer compound Winter Tires (UMP's I think)
instead of DR's because they stick like glue when warmed up, street legal, way more puncture resistant than DR's ...ask autobred.
Run them on all 4 corners and rotate them FTW!!!
I think stock 20" Alum/Chrome Clads are 34-36lbs each
and around 80lbs total with 275/60R20 Good-for-a-Year rubber
Mine with 305/50R20 TerraGrapplers are well over 90lbs ea.
My Moto Metal 17" x 9" wheels are just about 30lbs (32 lbs of DR = 62 lbs total)