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 Mazda-engineered powertrain under the hood, a 4-cylinder, 16-valves 140hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 130hp engine designed by FIAT.

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 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. On the other hand, if we'd like to consider vehicle mass in this context too, which we definitely should, the German car offers a marginal difference of 7% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning 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 Mazda with an average rating of 4.4, and models under the Opel badge with 4.2 out of 5. Independent research findings rank 6 as average reliability-wise, and Insignia is more or less at the same level.That apart, owners of different cars powered by the same engine as the Japanese car rank it on average as 3.5, while the one under the competitor's bonnet gets 4.9 out of 5.

Mazda is a bit more agile, reaching 100km/h in 0.6 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 204 kilometers per hour, 1km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 5.7 liters of fuel per 100 kilometers (50 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 slightly better overall protection and takes the lead. From there things take a different direction, with Mazda offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! No mistake, whatever you decide here, but I'd still go for the Mazda. 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. Also, you could use the oportunity to find out which car, everything taken into account, would be the perfect choice for you in the eyes of the virtual adviser™, among more than 12.000 different ones in our database.