Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Considering they both belong to the large family car segment and utilize the same 4-door sedan body style and the front wheel drive system, it all comes up to the specific diesel engine choice they offer. The first one has a General Motors-engineered powertrain under the hood, a 4-cylinder, 16-valves 136hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 136hp 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, but it doesn't do much to help us decide between the two. Furthermore, when it comes to weight, a factor that most people underestimate, Insignia offers a marginal difference of 1% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Opel does have a slight advantage, all the models observed together. That's the official data, while our visitors describe reliability of Opel, as well as Audi, with the same average rating of 4.2 out of 5. Independent research findings rank Insignia 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 Insignia rank it on average as 3.8, while the one under the competitor's bonnet gets 4.5 out of 5.

Audi is undoubtly more agile, reaching 100km/h in 1.6 seconds less than its competitor. In addition to that it accelerates all the way to 215 kilometers per hour, 5km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 3.9 liters of fuel per 100 kilometers (72 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, Insignia offers slightly better overall protection and takes the lead. From there things take a different direction, with Audi being considerably quicker, thus putting more smile on driver's face. Fuel consumption is more or less the same. It's really tough to make a final decision here, but if I'd need to, I'd say 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. 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.