The 2015 IndyCar manufacturers' battle was memorable for all sorts of reasons. It vindicated predictions that the arrival of aero kits would skew what had previously been a close fight between Chevrolet and Honda; a clash that achieved an organic type of parity through both sides doing an excellent job.
That clearly wasn't the case when the new aero bits were bolted on. Both needed revisions through the season, but the scorecard showed that the relatively simple and functional approach championed by Chevy's partner Pratt & Miller overwhelmed the elaborate but draggy-as-hell reply from Honda and Wirth Engineering.
The result is right there in black and white: Chevrolet beat Honda in the manufacturers' standings by 1645 points to 1179, including penalties of 480 points to Honda's 560 (most were for engines being changed before they reached their mandated 2500-mile lifespan). Chevy won 10 races to Honda's six. A Chevy sat on pole for every race of the year.