Two significantly similar cars, no doubt about that. Still, each one has something different to offer. Having both cars powered by petrol 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 BMW and front in the case of the Audi). The first one has a BMW-engineered powertrain under the hood, a 6-cylinder, 24-valves 192hp unit, while the other one gets its power and torque from a 6-cylinder, 30-valves 170hp engine designed by Volkswagen.

The first thing to look into here would be the results from European New Car Assessment Programme (Euro NCAP) tests performed on the two cars. Good thing is that both vehicles got tested, with the same number of safety stars gained in the process. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the large family car segment, which is generally a good thing safety-wise, still it doesn't help us solve our dilemma, does it? On the other hand, when it comes to weight, a factor that most people underestimate, Audi A4 offers a marginal difference of 1% 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, at least on all of the models level. That's the official data, while our visitors describe reliability of BMW, as well as Audi, with the same average rating of 4.2 out of 5. Independent research findings rank 3 Series as average reliability-wise, and A4 is more or less at the same level.Above it all, drivers of cars with the same engine as 3 Series rank it on average as 2.8, while the one under the competitor's bonnet gets 5.0 out of 5.

BMW is undoubtly more agile, reaching 100km/h in 1.5 seconds less than its competitor. In addition to that it accelerates all the way to 240 kilometers per hour, 14km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 9.3 liters of fuel per 100 kilometers (31 mpg), in combined cycle.

Audi 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, Audi A4 offers slightly better overall protection and takes the lead. From there things take a different direction, with BMW being considerably quicker, thus putting more smile on driver's face. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the BMW. 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. I suggest you spend two more minutes in order to find out which car, based on your needs and budget, would be picked by the virtual adviser™, among thousands of similar, yet so different vehicles.