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 front wheel drive system, it all comes up to the specific diesel engine choice they offer. Both the engines are Hyundai-engineered . The first one has a 4-cylinder, 16-valves 115hp unit, while the other one gets its power and torque from a 4-cylinder, 16-valves 136hp one.

The fact that the Hyundai 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. Moving further on, let's take a closer look at some additional safety-related facts. 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. On the other hand, taking kerb weight as an important factor into account, Optima offers a marginal difference of 1% more metal.

Reliability is not the best thing to consider on the make level, but it is worth mentioning that Hyundai does have a slight advantage, at least on all of the models level. These are the official statistics, while our visitors describe reliability of Hyundai with an average rating of 4.5, and models under the KIA 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 i40 rank it on average as 4.3, while the one under the competitor's bonnet gets 5.0 out of 5.

KIA is undoubtly more agile, reaching 100km/h in 2.6 seconds less than its competitor. In addition to that it accelerates all the way to 202 kilometers per hour, 10km/h more than the other car. When it comes to fuel economy the winner has to be i40, averaging around 4.3 liters of fuel per 100 kilometers (66 mpg), in combined cycle. We can't ignore that 14% difference compared to Optima.

KIA 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, i40 beats the other contender by far, making it the best choice without even considering other things. From there things take a different direction, with KIA being considerably quicker, thus putting more smile on driver's face. It does come at a cost though, and that's the fuel consumption... All together, there's not much more to say, in this case I wouldn't even consider anything but Hyundai. 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™, among thousands of similar, yet so different vehicles.