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 diesel engine choice they offer. The first one has a Renault-engineered powertrain under the hood, a 4-cylinder, 8-valves 110hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 150hp 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. Moving further on, let's take a closer look at some additional safety-related facts. Both vehicles belong to the small family car segment, which is generally classifying them somewhere in the middle safety-wise, but that fact doesn't break the tie between the two cars. Furthermore, taking kerb weight as an important factor into account, Q30 offers a marginal difference of 5% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Mazda does have a slight advantage, at least on all of the models level. These are the results of an independent reasearch, while our visitors describe reliability of Infiniti with an average rating of 4.5, and models under the Mazda badge with 4.4 out of 5. Unfortunatelly, I don't have enough insight that would allow me to comment in more details on the specific models level. Above it all, drivers of cars with the same engine as Q30 rank it on average as 4.2, while the one under the competitor's bonnet gets 5.0 out of 5.

Mazda is way more agile, reaching 100km/h in 3.9 seconds less than its competitor. In addition to that it accelerates all the way to 210 kilometers per hour, 20km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 4 liters of fuel per 100 kilometers (71 mpg), in combined cycle.

Mazda 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, Q30 offers slightly better overall protection and takes the lead. From there things take a different direction, with Mazda outracing its opponent in any situation possible, making it better choice for boy racers. It does come at a cost though, and that's the fuel consumption... It's really tough to make a final decision here, but if I'd need to, I'd say Mazda. 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. 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.