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 Mazda-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, 16-valves 170hp engine designed by Mercedes Benz.

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. 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 it doesn't do much to help us decide between the two. On the other hand, when it comes to weight, a factor that most people underestimate, Q30 offers a considerable difference of 12% more metal.

I don't like generalizing things when it comes to reliability, although it does seem that Mazda does have a slight advantage, all the models observed together. 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 Infiniti badge with 4.6 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 Mazda 3 rank it on average as 5.0, while the one under the competitor's bonnet gets 4.5 out of 5.

Mazda is a bit more agile, reaching 100km/h in 0.2 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 210 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 4.2 liters of fuel per 100 kilometers (68 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 significantly better overall protection, taking the lead here. 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. I suggest you spend two more minutes in order to find out which car, based on your needs and budget, would be picked by the virtual adviser™, out of 12.000+ vehicles we currently have in our database.