Hot weather testing is a automotive spy photographers dream. Not only do you have ample space to hide and pull up to a perspective prototype, but the lighting perfectly reveals all little details on a new car, you get the clear picture as they say.

Audi is the latest to fall victim to these circumstances and the new RS5 was caught out during hot weather testing in the hot Death Valley region of California. Whats worse is the car is plainly undisguised and it is clear to see what the new RS5 will look like. The foglamps have been removed in favor of extra breathing ducts to cool the engine and brakes, while the actual fog lamps have been moved probably to inside the headlights, similar to Audi’s recently released RS6.This prototype doesn’t yet display all the expected RS design cues but the front bumper is dead on, and unlike the stock S5 rear bumper, is nessaccery for final hot weather testing and to determine optimum radiator placement . The RS5 test mule still has the quad oval tips from the S5 too, but wearing silver side mirrors, another another indication of a high performance Audi. The flared fenders and big wheels are missing as they are not needed for this test and can be fitted later.

As far as engine choice is concerned rumours have been abound. Everything from a V10 to a twin turbo V8 have been mentioned but no one knows for sure. But I will reveal it now as a trusted source inside the company has revealed to me. Audi engineers are extremely pleased with the current Rs4’s performance. They are quite proud of their baby and want to develop it further. Knowing this it has been revealed to me that the new RS5 an Rs4 models will use a revised version of the current engine making north of 460hp. At 420hp the current 4.2-liter V8 is already making the mythical 100hp per liter usually reserved for racecar engine specs and stretched to it’s limits. It has already been divulged to me that the displacement will stay at 4.2-liters, so to achieve these figures Audi will probably incorporate some of it’s recent Variable Valve Timing technology to achieve these results. My insider say to expect an engine that will impress everyone, even the competition.

For now though, all we have are some spy shots:

Above: The tail end might say S5, but the front screams RS5….