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 5-door hatchback 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, 8-valves 120hp unit, while the other one gets its power and torque from a 4-cylinder, 8-valves 116hp engine designed by Renault.

Both vehicles got tested by European New Car Assessment Programme (Euro NCAP), with the same number of safety stars gained in the process. Moving further on, let's take a closer look at some additional safety-related facts. 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? Furthermore, taking kerb weight as an important factor into account, the German car offers a marginal difference of 3% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Nissan does have a slight advantage, at least on all of the models level. These are the official statistics, while our visitors describe reliability of Opel with an average rating of 4.2, and models under the Nissan badge with 4.3 out of 5. Independent research findings rank Vectra as average reliability-wise, and Primera 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 4.5, while the one under the competitor's bonnet gets 4.9 out of 5.

Nissan is a bit more agile, reaching 100km/h in 0.5 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 195 kilometers per hour, 5km/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.

Nissan 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 Nissan offering somewhat better performance, just enough to call it quicker. 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 Nissan. Nevertheless, let's not forget that people have different preferences and needs, so what really counts is your personal feel. I'm only here to help. 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.