Gordon Murray Automotive has got its first test mule for the T.50 supercar up and running.

The first thing you’ll notice about this mule is that it doesn’t look anything like the T.50. There’s a good reason for that as this is actually an Ultima that has been extensively modified to support the T.50’s 3.9-liter Cosworth V12 and six-speed Xtrac manual transmission.

The niche car manufacturer is using an Ultima to test the T.50 in order to get a jump start on development as the supercar’s carbon fiber chassis has yet to be manufactured. As such, this test mule will be used to calibrate the engine and emissions systems. It’s rather fitting that an Ultima chassis is being used as McLaren also used modified Ultima mules when first developing the iconic F1.

Read More: $3.1M Gordon Murray T.50 Is A 21st Century McLaren F1 That Weighs Less Than An MX-5

This particular engine is restricted to 4,000 rpm, but as the automaker continues the calibration of the powertrain, the revs will slowly build. Not only does the mule feature the V12 engine and the six-speed manual, but also the production-ready fuel and oil systems, as well as the T.50’s roof scoop. The prototype will soon head out testing at a number of circuits across Europe, including Nardo.

Cosworth has designed this 3.9-liter V12 specifically for the T.50. It churns out 654 hp and 344 lb-ft (467 Nm) of torque, can rev to an extraordinary 12,100 rpm and goes from idle to redline in just 0.3 seconds.

Production of the T.50 will be capped at just 100 units with prices starting at £2.36 million ($3.05 million) before taxes.