The battery produced by Interstate is a good choice and several owners use this one when replacing the XFire's battery. But there are lots of Interstate-sourced batteries as they produce for a wide variety of aftermarket sellers. I quit trying to keep up with battery producers & who they supply batteries for.

I have a Durcell Ultra in my Coupe now, having replaced the original Varta battery after 9 years. Started getting the weird-acting spoiler function, which is an early warning signal of a battery issue. Bought the Duracell from Batteries Plus when they had a fairly good sale. Duracell is sold by either Costco or Sam's Club, don't remember which, but either source typically has good pricing.

Only decision required is whether your want a conventional or AGM design. And another thing - batteries for the XFire do vary in casing size somewhat. The so-called standards used by the battery producers is short of being a standard (MHO). What we find is the height of the case varies enough that the holddown clamp doesn't fit exact. Some folks have had to add a rubber" spacer" under the clamp to get a secure fit. In my case, the Duracell case is slightly taller and I bent the clamp to avoid excessive side pressure on the leading edge.