YASA Limited

YASA is a British manufacturer of electric motors and motor controllers for use in automotive and industrial applications.[1][2][3] The company was founded in 2009 by the CTO Dr Tim Woolmer who is also the holder of a number of related motor technology patents.[4] Although initial commercial adoption was in high-performance cars, markets for YASA e-motors and generators now include the off-road, marine, industrial and aerospace sectors.

YASA Limited.
TypePrivate company
FoundedOxford, United Kingdom (September 2009)
Oxford, Oxfordshire
Key people
Dr Chris Harris, CEO
Dr Tim Woolmer,
CTO and founder
ProductsElectric motors
Motor controllers
ParentDaimler AG


YASA Limited (formerly YASA Motors Limited) was founded in September 2009 to commercialise a permanent-magnet axial-flux electric motor (YASA stands for Yokeless and Segmented Armature). The motor was developed for the Morgan LIFEcar in 2008 by Dr Malcolm McCulloch and Dr Tim Woolmer, then a PhD student, at the University of Oxford.[2][4][5] In 2015, YASA Motors launched the P400 Series of motors in serial production for volume manufacturers.[6] In January 2018, YASA's 1st series production facility, capable of 100,000 units per year, was officially opened[7] by the Rt Hon Greg Clark, UK Secretary of State for Business, Energy and Industrial Strategy.

In May 2019, the company announced "Ferrari selects YASA electric motor for SF90 Stradale, the company’s first hybrid production series supercar" [8]

On July 22, 2021, YASA Limited is acquired by Mercedes-Benz.[9]

Products and applicationsEdit

YASA 750 e-motor/generator. 790 Nm from 37 kg.

YASA offer a range of off-the-shelf and custom motors for use in a number of applications such as electric (BEV) and hybrid vehicle drivetrain,[10] power generation and hydraulics replacement systems.[11][12]

Standard Motors and ControllersEdit

YASA's standard electric motors have been used in several high-performance cars such as the Drive eO PP03 (the first EV to win the Pikes Peak International Hill Climb outright),[13] Jaguar C-X75, Koenigsegg Regera,[14] and a Lola Le Mans Prototype converted by Drayson Racing, which set a world electric land speed record in 2013.[15][16]

YASA P400 SeriesEdit

The YASA P400 series of electric motors produces up to 160 kW (210 hp) peak power at 700 V and 370 N⋅m (270 ft⋅lb) of peak torque at 450 Amps.[17] At this peak power, the off-the-shelf P400 Series achieves a power density of 6.67 kW/kg (4.06 hp/lb), with continuous rating of up to 100 kW (130 hp). The stator of the P400 series motors is oil cooled, and can optionally include additional air cooling.[17]

YASA 750 REdit

The YASA 750 R is the larger and more powerful electric motor in YASA's standard range, producing up to 200 kW (270 hp) of peak power at 700 V and 790 N⋅m (580 ft⋅lb) of peak torque. Continuous operating power for the 750 R is stated at up to 70 kW (94 hp).[18]

YASA Si400 ControllerEdit

The Si400 controller delivers 200 kVA from a 5-litre package weighing just 5.8 kg (13 lb). The controller features innovative thermal management including dielectric oil cooling and is suitable for use with induction, permanent magnet and axial-flux electric motors. The Si400 became available for sale on 2 April 2019. YASA launches new series of motor controllers

complete 2-speed electric drive unit

Custom Powertrain Solutions: E-Motors, Controllers & Integrated Electric Drive Units (EDU)Edit

As well as standard products, YASA designs and manufactures e-motors that are fully integrated into the drivetrain of their OEM and Tier 1 automotive customers. The e-motors feature power densities up to 15 kW/kg (9.1 hp/lb)[19] in vehicle applications that include P2 Hybrid Vehicle Powertrain,[20] P4 traction motor for e-axle[19] and REx (range-extension).[21]


  1. ^ "YASA Limited.: Private Company Information – Businessweek". Bloomberg L.P. Retrieved 4 March 2015.
  2. ^ a b "Oxford YASA Motors Shows Specific Torque Above 30Nm/kg". Green Car Congress. Retrieved 4 March 2015.
  3. ^ "Lloyds/Telegraph awards reveal the best British entrepreneurs". The Daily Telegraph. Retrieved 4 March 2015.
  4. ^ a b "Light electric motor spins out". Phys.org. Retrieved 4 March 2015.
  5. ^ "Special commendation: Electric avenue". The Engineer. Retrieved 4 March 2015.
  6. ^ YASA Motors. "YASA Releases New Motor and Generator Products for Serial Production". yasa.com. Retrieved 15 October 2015.
  7. ^ "Electric vehicle motor factory opens in Oxfordshire". news.bbc.co.uk. Retrieved 14 August 2019.
  8. ^ "Ferrari selects YASA electric motor for SF90 Stradale". BusinessWire.com. Retrieved 14 August 2019.
  9. ^ "Mercedes buys UK start-up Yasa as it steps up electric transition". Financial Times. Retrieved 1 October 2021.
  10. ^ "YASA motors for hybrid vehicles". yasa.com. Retrieved 19 January 2016.
  11. ^ "YASA Limited " Standard Electric Axial Flux Motors – YASA 750R, YASA P400R,". YASA Limited. Retrieved 4 March 2015.
  12. ^ "YASA Limited " Hybridisation – Integrated Electric Motor and Engine Applications". YASA Limited. Retrieved 4 March 2015.
  13. ^ Pikes Peak - Emergence of Electric Vehicels
  14. ^ "Koenigsegg charges forward with 1,500-hp Regera hybrid hypercar [w/video]". Autoblog.com. Retrieved 4 March 2015.
  15. ^ "Drayson Racing electric car sets new world speed record". BBC News. Retrieved 4 March 2015.
  16. ^ "Britain claims electric land speed record!". BBC. Retrieved 4 March 2015.
  17. ^ a b "YASA Motors " P400 Series,". Retrieved 5 February 2016.
  18. ^ "YASA-750 Compact Axial Flux Electric Motor | Advanced Manufacturing". YASA Limited. Retrieved 14 March 2018.
  19. ^ a b "P4 Traction and EDU > YASA Limited". YASA Limited. Retrieved 11 June 2018.
  20. ^ "P2 Hybrids > YASA Limited". YASA Limited. Retrieved 11 June 2018.
  21. ^ "Motors for Range-extended Generators > YASA Limited". YASA Limited. Retrieved 11 June 2018.

External linksEdit