He is notable for winning the Finnish, Northern European Zone (NEZ) and Estonian Formula Renault championships.

However, despite finishing behind Salo and Häkkinen in the championship, Pertti's career never went beyond Scandinavia, excluding a one-off appearance at Brands Hatch for the Formula Ford festival.

With a number of successes the previous year, Krohn entered the UK Formula Renault championship for the whole season where he has so far tallied 117 points, including a win at Thruxton.

Krohn gained some notoriety during the year as well after climbing up from twenty–fifth to seventh in the wet conditions at Donington Park but soon dropped out of the point after his suspension failed and so had to complete the final three laps on three wheels, "exactly what Jan Magnussen would have done" commented Mark Burdett Motorsport engineer Andy Miller, who ran the Danish driver during his 1994 British Formula 3 campaign.

[1] 2014 saw Krohn admitted into the BMW Motorsport Junior Programme in which he trained in for three years, with established works drivers like Dirk Adorf and Jörg Müller.