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 small 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 petrol engine choice they offer. The first one has a Nissan-engineered powertrain under the hood, a 4-cylinder, 16-valves 125hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 140hp engine designed by Opel.

The fact that the Opel got tested by the European New Car Assessment Programme (Euro NCAP), while the other contender didn't, puts it sky-high safety-wise, in my eyes at least. That aside, let's consider some other aspects which affect safety. Both vehicles belong to the small family car segment, which is generally classifying them somewhere in the middle safety-wise, still it doesn't help us solve our dilemma, does it? Furthermore, when it comes to weight, a factor that most people underestimate, the Japanese car offers a marginal difference of 2% 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. That's the official data, while our visitors describe reliability of Nissan with an average rating of 4.3, and models under the Opel badge with 4.2 out of 5. The same official information place Tiida as average reliability-wise, and Astra is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as the Japanese car rank it on average as 3.0, while the one under the competitor's bonnet gets 4.5 out of 5.

Opel is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. In addition to that it accelerates all the way to 208 kilometers per hour, 18km/h more than the other car. When it comes to fuel economy the winner has to be the German car, averaging around 7.1 liters of fuel per 100 kilometers (40 mpg), in combined cycle. We can't ignore that 10% difference compared to the Japanese car.

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 beats the other contender by far, making it the best choice without even considering other things. It all continues in the same direction, with Opel offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! All together, there's not much more to say, in this case I wouldn't even consider anything but 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. 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™, out of 12.000+ vehicles we currently have in our database.