Ever wonder what the difference between all the sports line each brand offers? I'm going to explain the differences between Audi, BMW and Mercedes in terms of their S, RS, M, and AMG lineups.
Here are the following badges from each brand that lets you know which of their cars is performance oriented. However, don't be fooled by the badging, because some of these cars with badges don't actually mean that they are full blown ready for the track.
Building a car to be track ready and having a car that drives faster than most on the streets is different. For example the upcoming M340i and the S4 are all great cars but the purpose is not for the track. I guess you could take it to the track but it wouldn't be suitable as an M2 or C63 AMG.
Let's just talk performance sedans and coupes for now, because every brand has its performance SUV line as well. For Audi, the normal sedan lineup is denoted by Ax where x is the series, for example A4, A6, A7 etc. The next step up is the Sx line such as the S3 and S4. This lineup is meant to be a sporty daily driver. The suspension is firmer but not too much so it won't be uncomfortable. The interior styling is a bit different for a more aggressive feel. The RSx lineup like the RS5 is Audi's full blown performance lineup. It has all the best stylings and build materials in these cars.
When we look at BMW, the Mxxx lineup is comparable to the Audi Sx lineup. For example the M340i will be similar in performance to the S4. The next step up is the Mx lineup such as the M2, M3 and M5. These are full out track ready cars that don't need modification to go out and have fun. If there is more than one number after the M badge then it's not a full out track ready vehicle. There may be packages that make it more track capable but it's not the same as an Mx car.
From Mercedes there is the AMG lineup. However, this segment is more difficult to understand. For example the C43 AMG is comparable to the Audi S line but the C63 AMG is comparable the RS lineup. You might ask how will I know which one is which? Unfortunately, it's not very apparent from the naming scheme. I guess the easiest way is to tell by the price. The most expensive AMG in each class will be the track ready vehicles. However, I don't think an owner of an S63 AMG would ever take that to the track. Then there is the AMG S badge you might see every so often. The S added just means that there is more HP. This will only be only on full blown AMG track ready vehicles. I know there might be exceptions to everything I'm saying but this is generally true for the CLA, C and E classes.
I hope this helps clear up some confusion about all the different performance oriented lineups from each brand. I know it's confusing so hopefully I didn't make this even more so
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