Tire brands and warranties
How could the warranty be so different but so close on price?
Probably different warrenty details. They probably both cover defects in manufacturing, and if include some sort of prorating on wear, its probably just pennies at the higher milages. (for example see post #2 )
Road warrenty is different again. If you're not paying extra, then its built into the pricing.
Are Firestone's even made in USA anymore?
Some are. Such as these.
https://www.tirerack.com/tires/tires.jsp?tireMake=Firestone&tireModel=Destination+A/T Go to the 'Spec' tab and it shows that on the far right column.
My suggestions are:
Brand
Low priority, unless you know that there are certain brands you just couldn't stand seeing on the sidewall every time you got in the car. It doesn't have to make sense. It could be because 20 years there were a bunch of recalls by that company, or you just think it looks visually wrong. If you don't want 'em, don't buy 'em.
It is true some companies have targetted certain markets, may have different QC strategies, etc. But just because it says Hankook on it, doesn't mean its a super sticky high performance summer tire. Specific model may be as mundane as the next company's basic tire.
Milage Ratings
If you're putting on a lot of miles each year, use that along with cost to figure your budget. If you can't afford another X dollars for tires until 2022, then the treadwear ratings become important. The UTQG treadwear ratings are based on tires within the manufactures line.
UTQG Traction and Temperature Ratings.
Give these some consideration. A traction rating of A might well be worth a few extra bucks over a similar tire with a rating of B.
Tread and Internal Construction
This should be a high priority. Always choose a tire most appropriate for the conditions its going to be used in.
