Tires: Spare tire, ford windstar, bridgestone turanza

Question
Barry,

QUESTION #1:
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I currently have a full-size spare tire on my Ford Windstar.  It's a Bridgestone Turanza LS-T.  I need to replace the four tires I'm currently using (same type of tires).  Is it best to buy three new, identical Turanza LS-T tires, use the spare tire as the fourth tire, and then use one of the old tires as the spare?  If I did this, could the new spare tire (the old, used tire) be used on either side of the vehicle in an emergency, i.e., can it spin in either direction?  The old tires have enough wear on them that I could still get several hundred miles out of them.  All five current tires (including the spare) are about 5 years old.

QUESTION #2
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The tires on my Windstar are 225/60R16 (they are not the original tires.)  When I do a search on line for the type of tire recommended for this vehicle, it shows 215/65R16.  Why are the first two numbers different (225 and 60 vs. 215 and 65)?

Thanks,
Matt Stout  

Answer
Matt,

The current discussions coming out of the tire industry is that tires deteriorate over time (I guess we all knew that), but they've published some guidelines.  Some folks are saying 6 years is the limit - even if the tires are unused - and some are saying 10 years.  My take is that the different is the ambient temperature where you live.  Phoenix gets really hot where Minneapolis, doesn't.

I'm thinking your 5 year old tire is likely too old to be used for anything except a temporary spare (meaning 10 to 20 miles).

The number have a meaning and they mean the tire size was changed to something a bit more common.

Look up Tire Rack's web site and go to their Tire Tech area.  They can explain tire sizing better than I can using this medium.