2018 and 2013 axles interchangable?
 

I saw my axles leaking, lowered 1.5 in. And there is a clicking noise, i have not tracked it down yet. But it might be the axles. Can i put 2018 axles on 2013 frs? Is there any benefit to it?

Yes they are interchangeable, but no benefit as it's the same part.

I would recommend buying axles off ebay instead of brand new but thats just me.

New they are $800 for the pair, but I bought a used set with 32k miles for $175 that are still in excellent condition 20k miles later.

Also I'd never buy anything but OEM axles, some of the off brand stuff is junk.

Sage advice. I cant speak directly for the frs/brz axles but ive never had an issue with good condition used axles vs non OE new axles... the clicking is stupifying

I'd also look for wreaked cars being parted. I have a set of spares I picked up used out of a wreaked car a while ago. I believe I also paid around 150-175 for the pair. If you are replacing axles, I would buy new axle nuts as well. I haven't had much luck reusing them.