AMG and Mercedes:
AMG is the first comercial car to use a “Hot V” configuration for the Turbos, which came because of F1, this “Hot V” configurations gave Mercedes 3 dominant championships in F1 *This is also used on all Mercedes-AMG Race Cars
Mercedes is the first company to mass produce a vehicle with Portal Axles (G-Class 4×4 Squared)
Audi has arguably the best AWD system on the market.
Audi has won most of the past 10 years at Le Mans with the R prototypes
Both companies have a big motorsport reputantion (DTM, F1, WEC)
So I would say in the power train point of view they are pretty equal, even tough Mercedes engines are known to be more reliable, on the power font, they are pretty similar (ex:RS7 and E63S)
All of them are great cars, if you’re looking for sheer luxury go for Mercedes, if you’re looking for a great driving experience, go for BMW, but if you want something in between all of that, you’ll want an Audi. Audi has always been innovating in its tech, such as the optional virtual cockpit, and yes I know that BMW, Mercedes and even VW have them aswell, but none are as crisp and easy to use as Audis. Maybe perhaps the one thing that lets it down would be styling, audis are always neat, tidy and organised. Some would say it’s boring, but I for one tend to like it. However you can’t complain about the interior design, the quality indeed is just a cut above the competition. One final thing, Audi is really up there with Volvo or even ahead when it comes to safety.
It’s quite unfair to compare these three legendary car makers because they have their own legacy benz maintain luxury(Maybach series) while BMW is meant for high safety vehicle(5 series) and Audi has excellent performance in high speed cars (R8,R6)
So we can’t actually distinguish these three it depends on the need of buyer!.
Individually? I’d vote MB. If you bring in the engineering powerhouse that is the entirety of the Volkswagon-Audi family, Audi might have the edge. It is a close race though.
BMW is great, but I haven’t seen quite as much raw innovation. Maybe I just haven’t been exposed to it.