Here's what's been updated.
Earlier this week, Nintendo rolled out the Wave 4 DLC for Mario Kart 8 Deluxe on the Switch. The patch notes specifically mentioned how Version 2.3.0 improved the performance of "some characters and vehicle customisations" and now we know what exactly has been updated.
Here's the rundown courtesy of the Japanese website Mario Kart Blog via Meester_Tweester on the Mario Kart subreddit) - explaining how most racers have had their ground, water, air and anti-gravity speed stats increased. Other characters, vehicles and tires have also had their mini-turbo values increased.
Read the full article on nintendolife.com