Subaru Impreza Wrx Sti Gear Ratios. I also noted that the sti's are listed as having 305bhp in the us, whereas here they're listed as 300bhp. P.s., if anyone's interested in all of the ratios, here they are so you don't have to look 'em up:
Instead of searching for differential ratios, try final drive ratios. Believe it or not, some of the older wrxs and sti's come with up to a 440 diff. Not as close ratio as the type ra kit and 4th and 5th gear ratios match the wrx meaning highway rpms and fuel economy will be unaffected.