Large disc brakes and calipers hiding behind 20-inch multi-piece rims and quad exhaust tips in spy photos suggested Audi was developing an "S" line version of the Q5. But could last month's spy photos of Audi's Q5 really a Porsche Cajun test-mule? British magazine Autocar seems to think so, which would go along with Audi's assertion that they have no desire to develop S or RS versions of any of its SUVs.

Now European auto magazine Autocar hints that the SQ5 we caught testing could really be the test mule for the upcoming baby Porsche SUV. The Porsche Cajun will share platforms and some drivetrains with the Q5 to lessen R&D and component costs, thus further strengthening ties between the two brands.

One engine the two SUVs will share will be Audi's 309 hp, 479 lb-ft twin-turbo 3.0-liter V6 diesel. The oil-burner will be the top engine for the European models. Audi's head of engine development, Axel Eisner, indicated to Autocar that the new twin-turbo 3.0-liter V-6 diesel will eventually make its way to the A4, A5, A6, A7, A8 and Q7. Eisner denied the engine will power as a new line of diesel-powered S models, but he confirmed a twin-turbocharged four-cylinder diesel is in the works, likely for the A3.

No word yet if the twin-turbo V-6 diesel - or the twin-turbo four-cylinder oil-burner - will make it to our shores in the Q5 or the Cayenne's baby brother. It's likely that we could receive both engines, because Audi reportedly desires to expand its use of diesel engines stateside. The current engine lineup in the U.S. for Q5 models are the 211 hp and 258 lb-ft of torque 2.0L turbocharged four-cylinder engine and a step up to the 3.2 FSI V6 rated 270 hp and 243 lb-ft of torque.

Source: Autocar