Deliveries of Mercedes-AMG's hypercar, One has been reportedly delayed till 2021 as there are ongoing difficulties in making the engine suitable for street use.

According to Auto Motor und Sport, some parts of of the One’s powertrain is in need of refinement as engineers underestimated the difficulties posed by using such an highly-strung engine.

One of the most significant challenges includes making the Formula 1-inspired 1.6-litre turbocharged V6 pass its WLTP emissions regulations. The Germany company has also been reported to face issues in making sure that the engine doesn’t require electric pre-heating before it turns over, like a race engine does. With such a high power output targeted by the company, the engineers also realised that squeezing more than 650bhp from the 1.6-litre engine could make it a tad fragile.

The hypercar is set to have a combined output of more than 1,000bhp thanks to the help of four electric motors. This would allegedly be enough to send the hybrid hypercar to 200 km/h in less than six seconds and through to a top speed over 350 km/h.