Upgrading mustang v6 2017's exaust/mufflers

So, I got a new mustang v6 2017 and I heard that you can upgrade the exaust to make it sound like v8. So, my question is how muc does it cost to buy a new one and getting it installed? Any cheaper ones out there with some decent quality? Does upgrading exaust/mufflers drops mileage? Does it drops horsepower? Does it impacts the engine anyways? Does it has any impacts on its 5year free warranty by ford?

Depending on the one chosen it very possibly could void the warranty, so you should investigate that possibility. It's not worth spending the money on because it will probably reduce the fuel mileage. If you wanted the sound of a V8 you should have bought a V8.

Doesn't matter what you do, it's not going to sound like a V8. Just a louder V6. Number of cylinders and their firing order just makes it sound different. Done properly you may get slightly more power (maybe) and it shouldn't harm fuel economy.

Main problem is you make the car annoyingly loud, and end up with a "drone" noise cruising at highway speeds.

" I heard that you can upgrade the exaust to make it sound like v8."

You heard wrong. V8's sound the way they do due to timing of the exhaust pulses. Your V6 lacks the necessary number of cylinders to make that happen. You certainly can get an aftermarket exhaust that make louder, but it's not going to have the same low rumble as a V8.

"So, my question is how muc does it cost to buy a new one and getting it installed?"

For the S550 V6 you can expect to pay around $450-$700 for an axle back system, which is basically a pair of mufflers. Catback systems, which typically replace the stock resonator with a X pipe, and replace everything from the downstream of the cats result in greater difference in sound than axlebacks on the S550 cars. They typically cost around $850-$1300. Installation will cost around $150-$250 for axlebacks (cutting is almost always involved) to around $300-$400 for a catback-system. (usually bolt-on for 15+ Mustangs).

"Any cheaper ones out there with some decent quality? "

You get what you pay for. For the V6, the Borla ATAK catback is pretty aggressive sounding, but it's not cheap.

" Does upgrading exaust/mufflers drops mileage? "

No

"Does it drops horsepower? "

No

"Does it impacts the engine anyways? "

Not really, as long as the factory cats are in place.

"Does it has any impacts on its 5year free warranty by ford?"

Technically it can. Unless you buy the Ford Racing/ Ford Performance-branded parts and have either a dealer install them or an ASE-certficed mechanic. I have a Ford Racing (Borla) Sport catback on my 2016 Mustang GT, as well as a Ford Racing (Barton) short shifter. I also have a Stage 2 Power Pack on order. My warranty is intact as I had the installs done at the dealership where I bought my car. With that said Ford Racing/Performance does not currently offer an exhaust for the S550 V6, and with the V6 going away in 2018, I wouldn't expect them to market one. I've never seen a warranty denied because of an aftermarket exhaust, but technically if they can prove that the modification caused the failure, then they can deny your warranty claim.