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 2-door cabriolet 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 150hp unit, while the other one gets its power and torque from a 4-cylinder, 8-valves 130hp 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. 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, if we'd like to consider vehicle mass in this context too, which we definitely should, the German car offers a marginal difference of 8% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Renault 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 Renault badge with 4.1 out of 5. Independent research findings rank Astra as average reliability-wise, and Megane is more or less at the same level.We should definitely mention that owners of cars with the same powertrain as the German car rank it on average as 4.1, while the one under the competitor's bonnet gets 4.0 out of 5.

Renault 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 203 kilometers per hour, 10km/h less than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 6 liters of fuel per 100 kilometers (47 mpg), in combined cycle.

Renault 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 Renault 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 Renault. 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 thousands of similar, yet so different vehicles.