The RS 7 has 560 hp. The S 8 has 520 hp with the same engine. Does anyone know what the difference is? Is the turbo boost pressure higher or something else? Can the boost be turned up by an Audi dealer so the warranty remains intact ? Thanks in advance for any assistance.

 

The S6 and S7 have an identical engine. The S8 has a slightly beefier set up that allows more boost (thus more HP). The RS7 has even more stuff to help get it safely to 560 HP, so it's not exactly the same as the S8 engine. Audi will not tune your engine, however, there are a couple reputable tuners (mainly APR) that will have full tune that will increase overall power still within safe levels.