Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by diesel engines and utilizing the 4-door sedan body style within the same 'Large family car' segment, the only major difference here really is their wheel drive configuration (rear for the Mercedes Benz and 4 x 4 in the case of the Audi). The first one has a Mercedes Benz-engineered powertrain under the hood, a 6-cylinder, 24-valves 224hp unit, while the other one gets its power and torque from a 6-cylinder, 24-valves 233hp engine designed by Audi.

A starting point here would be to take a look at the results from European New Car Assessment Programme (Euro NCAP) tests which were performed on both of the cars, with the Mercedes Benz being a slightly better choice apparently. Moving further on, let's take a closer look at some additional safety-related facts. Both vehicles belong to the large family car segment, which is generally a good thing safety-wise, but it doesn't do much to help us decide between the two. On the other hand, taking kerb weight as an important factor into account, Audi A4 offers a marginal difference of 5% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that both brands display similar results in faults and breakdowns, all the models observed together. That's the official data, while our visitors describe reliability of Mercedes Benz with an average rating of 4.3, and models under the Audi badge with 4.2 out of 5. Some independent research have also placed C as average reliability-wise, and A4 is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as Mercedes Benz C rank it on average as 4.5, while the one under the competitor's bonnet gets 4.6 out of 5.

Audi is undoubtly more agile, reaching 100km/h in 1.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 245 kilometers per hour, 1km/h less than the other car. When it comes to fuel economy the winner has to be Mercedes Benz C, averaging around 6.9 liters of fuel per 100 kilometers (41 mpg), in combined cycle. We can't ignore that 10% difference compared to Audi A4.

Mercedes Benz appears just a bit more reliable, although the difference is truly marginal. The most important thing when deciding between any two vehicles should always be safety, both passive and active. In my opinion, everything taken into account, Mercedes Benz C offers slightly better overall protection and takes the lead. From there things take a different direction, with Audi offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... It's not difficult to say then that if I'd need to make a choice, it would definitely be the Mercedes Benz. In any case that's my personal view, built upon all the data available to me. What should decide here though is the way you feel about the two vehicles, and I hope you'll find my guidelines useful in the process. In case you have two minutes to spare I invite you to define your needs, desires and budget and see which car would be chosen by the virtual adviser™, among more than 12.000 different ones in our database.