It’s hard to believe that it’s been almost six years since we first laid eyes on Rimac’s Concept_One. Since then the company has been signing OEM supply deals to boost its revenues while also continuing to refine its electric supercar.

As Rimac signs up dealers for the Concept_One, including one in the United States, the company has announced some key performance upgrades. These fall into the powertrain, electronic control systems and battery areas.

The main upgrade is an additional 134 horsepower, bringing total output of the car’s four electric motors to 1,206 horses. This enables the Concept_One to now hit 60 mph in just 2.4 seconds, 124 mph in 6.0 seconds, and 186 mph in 14.0 seconds. The top speed remains at 220 mph.

The extra power required a bigger battery so Rimac increased capacity to 90 kilowatt-hours, up from 82 previously. Rimac says it also refined the torque vectoring system which can individually control the torque at each wheel.

Rimac Concept_One

Rimac Concept_One

Construction of the body and internal structure is almost all carbon fiber. The material was chosen to ensure stiffness as well as reduced weight. The Concept_One is still a heavy beast, though.

The bigger battery has added some extra weight to the car, with the new curb weight measuring a substantial 4,190 pounds, or 110 more than before. The quoted range is 217 miles, though this will depend heavily on how the car is driven.

Rimac’s dealership in the U.S. is New York exotic car specialist Manhattan Motorcars. It has also signed up Germany’s PACE, located near the city of Aachen, and the Alzarooni Group in the United Arab Emirates.

Rimac’s main business continues to be the supply of electric car technology to global OEMs. The company recently expanded its main facility located west of Zagreb and increased its number of employees to over 250. Among Rimac’s list of clients are automakers Aston Martin and Koenigsegg and motorsport team Monster Sport.