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 4-cylinder, 16-valves 177hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 170hp engine designed by Volkswagen.

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 BMW being a slightly better choice apparently. Still, apart from the official crash test results there are other things we need to be aware of. 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, when it comes to weight, a factor that most people underestimate, Audi A4 offers a marginal difference of 6% more metal.

Manufacturers have been building their reliability reputation for decades now and, generally speaking, it appears that both brands display similar results in faults and breakdowns, when all the models are taken into account. That's the official data, while our visitors describe reliability of BMW with an average rating of 4.1, and models under the Audi badge with 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.We should definitely mention that owners of cars with the same powertrain as 3 Series rank it on average as 3.0, while the one under the competitor's bonnet gets 5.0 out of 5.

BMW is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 225 kilometers per hour, 5km/h less than the other car. When it comes to fuel economy the winner has to be Audi A4, averaging around 7.1 liters of fuel per 100 kilometers (40 mpg), in combined cycle. We can't ignore that 25% difference compared to 3 Series.

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, 3 Series offers slightly better overall protection and takes the lead. When it comes to performance, both vehicles provide similar experience, so I wouldn't point any of them out. Audi A4 , on the other hand, consumps significantly less fuel, and that's a big plus. It's not difficult to say then that if I'd need to make a choice, it would definitely be the Audi. 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.