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 FIAT-engineered powertrain under the hood, a 4-cylinder, 16-valves 195hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 175hp engine designed by Mazda.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the same number of safety stars gained in the process. 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. Furthermore, taking kerb weight as an important factor into account, the German car offers a considerable difference of 12% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Mazda does have a slight advantage, when all the models are taken into account. These are the results of an independent reasearch, while our visitors describe reliability of Opel with an average rating of 4.2, and models under the Mazda badge with 4.4 out of 5. Independent research findings rank Insignia as average reliability-wise, and 6 is more or less at the same level.That apart, owners of different cars powered by the same engine as the German car rank it on average as 5.0, while the one under the competitor's bonnet gets 4.5 out of 5.

Mazda is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 216 kilometers per hour, 14km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 4.8 liters of fuel per 100 kilometers (59 mpg), in combined cycle.

Opel 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, the German car offers significantly better overall protection, taking the lead here. From there things take a different direction, with Mazda offering somewhat better performance, just enough to call it quicker. It does come at a cost though, and that's the fuel consumption... I believe that, when we take all into account, we have only one winner here - the Opel. 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™, out of 12.000+ vehicles we currently have in our database.