Kart racing 2006-2010
- Several podiums in national series
International breaktrough year 2011 in Formula BMW Talent Cup
- BMW Motorsport factory team driver
- 13 heats:
- 2 fastest lap times
- 3 times on the front row in qualifying
- 4 times on podium
- among the top 5 or better in 7/13 heats
- the fastest in the rain
- BMW Talent Cup leader Sebastian Herke: " Lassi was without a doubt one of the fastest race drivers in the series."
Year 2012: Lassi raced for the championship in British Formula BMW-series with Falcon Motorsport
- Oulton Park: The motor blew up in practice session, 7th in the race with a spare car.
- Donington: 2nd in qualifying, 3rd in the race.
- Brands Hatch: battle for the second place ended up in the wall.
- Snetterton: 6th in the race
- Thruxton: pole position, two times 3rd in the race
- Pembrey: 4th in the race
- Rockingham: did not race
- Croft: did not race
- Final results in the series: 6th
Season 2013: Falcon Motorsport
Lassi Halminen made another year contract with Falcon Motorsport. This time he wanted to race in Formula Ford of Great Britain season 2013. Falcon boss Nick Streatfield evaluated Lassi's chances before the season start:
"Lassi was very impressive last year. His pace was good although things didn't go his way as they should have. He's a typical Finn in terms of his style and he will adapt very quickly to Formula Ford. We are expecting good thing from him."
- Brands Hatch: 4th, 4th and 5th
- Donington: 3rd, 5th and retired from 3rd
- Thruxton: retired from 2nd (engine failure), engine failure, retired after two laps (turbo failure)
- Croft: 4th, 5th and retired from 3rd (gear lever failure)
- After Lassi had lost the chance to win the championship he retired from the series.Â
2014 Cancelled GP3 season followed by single raceweekend in Formula Renault 2,0 NEC and testing
- Prenegotiated GP3 contract was cancelled just before the season start due to a key sponsor's withdrawal
- Single Race weekend in Formula Reanult 2,0 NEC with PositioOne team at Silverstone, No podiums.
- Hundereds of testing laps with Formula Renault 2,0 resulted an unofficial track record in Alastaro motorcircuit:
- See the link on Lassis driving: https://www.youtube.com/watch?v=MhA5t55TcvI
VLN Series, Germany, in 2015
- Testing with BMW 235i on spring, but the start of racing with Priconracing took place until summer due to missing Nordschleife spesific lisence. Additionally, ongoing mandatory military service and the Matriculation Exams took some extra effort limiting the possibility for racing in 2015.
- Positive feelings from the single races in VLN, No podiums though.