Toyota recently took its Prius Plug-In to the Nürburgring track for an unusual experiment to check how little fuel it could use on a single lap.

Well, it seems that after a few modifications by Toyota's racing division, fuel economy went through the roof, which typically is what fuel prices do.

The result on 12.9 miles is 698 mpg at an average speed 40 mph as the 1.8-litre Atkinson cycle petrol engine backup turned on only for a while! This is more than 5 times better than official 134 mpg numbers.

"Motoring journalist and Japanese car expert Joe Clifford was tasked with the driving duties, taking the wheel of a standard Prius Plug-in he has recently upgraded with the addition of TRD parts – styling rather than performance elements that improved the car’s appearance rather than made it more fuel-efficient."

"In dry, breezy conditions, he recorded 698mpg, completing his lap in 20 minutes and 59 seconds. This far outstrips the car’s official combined cycle figure of 134mpg; in fact the Toyota used less than five tablespoons of fuel to do the job."

Clifford state:

“We used no special tricks for this test. We simply took a fully charged car, fitted it with low rolling resistance tyres and drove the lap, among all the other public drivers taking the opportunity to experience the challenge of the Nürburgring."

“Although the 12.9-mile distance is similar to a typical commuter trip, the difference here is a rise and fall in elevation of around 1,000 feet. In fact it was only on one long climb that the petrol engine cut in, and then only for a short while. Without that, we think we might have even achieved the ultimate 999.9mpg read-out – the highest figure the display can show."

Well... maybe just increase the size of lithium-ion battery pack to achieve 999.9 mpg in the next generation?

"Prius Plug-in’s achievement adds to the history of Toyota’s Nürburgring success, including lap records for its EV P001 and P002 electric vehicles. More importantly, this latest test relates directly to what customers might experience with their own vehicle in day-to-day journeys. In a neat link to the record-breaking exploits of the EV P002, the battery cells from that car were used to power up the Prius Plug-in, via Toyota Motorsports’ charging truck."