Hennessey's community service - at 354km/h

Hennessey Performance have milked over 1200hp (915kW) out of this Caddilac CTS-V. Photo / Supplied

Gotta love Texas, where everything is big - including the speed limits.

A stretch of highway has been given an 85mph (136km/h) speed limit, and in the interests of community safety its licence plate reading systems needed to be tested at higher speeds.

Enter Texas' fastest car company, Hennessey, and you've got a balls-out 220mph run past some plate recognising toll cameras - think Puhoi tunnel at 354km/h.

John Hennessey told US car blog Jalopnik that he ran into Texan Lt Governor David Dewhurst and mentioned that he'd be able to supply a couple of quick cars to help test the TxTag toll system on the SH-130 before it opened last month.

The politician had a chat to the Transportation Department, and the result was Hennessy's twin-turbo 7-litre, 913kW (1226hp) Cadillac CTS-V VR1200 flying past the cameras about as quickly as you could ever do it.

And then, for good measure, he did it in his Camaro - allegedly the fastest ZL1 in the world, at 328km/h - just in case.

The plate reading system worked, capturing front and rear licence plates at around 180mph (289km/h).

"This was a win-win for our company as well as the state and TxDOT," the tuning legend told Jalopnik.

"I am truly proud to be a Texan and from a state that has the best highway system in America. We also have some of the best people who work together to get things done!"

- nzherald.co.nz