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 4-door sedan body style and the rear wheel drive system, it all comes up to the specific petrol engine choice they offer. The first one has a Toyota-engineered powertrain under the hood, a 4-cylinder, 16-valves 245hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 211hp engine designed by Mercedes Benz.

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 large family car segment, which is generally a good thing safety-wise, but that fact doesn't break the tie between the two cars. Furthermore, if we'd like to consider vehicle mass in this context too, which we definitely should, Lexus IS offers a marginal difference of 7% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that Lexus 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 Lexus with an average rating of 4.9, 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. We should definitely mention that owners of cars with the same powertrain as Lexus IS rank it on average as 5.0 out of 5, exactly the same as the other one.

Lexus is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. Still, it lacks the power to win the top speed competition, topping at 230 kilometers per hour, 15km/h less than the other car. When it comes to fuel economy the winner has to be Q50, averaging around 6.3 liters of fuel per 100 kilometers (45 mpg), in combined cycle. We can't ignore that 11% difference compared to Lexus IS.

Lexus 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, Lexus IS offers slightly better overall protection and takes the lead. From there things take a different direction, with Infiniti offering somewhat better performance, just enough to call it quicker. To make things even better, it consumps less fuel! I believe that, when we take all into account, we have only one winner here - the Infiniti. 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™, among more than 12.000 different ones in our database.