Well, these are two pretty similar cars we have here! It's only details that could potentially make the difference. Not only that they both belong to the large family car segment and utilize the same 4-door sedan body style, they are even powered by the same Hyundai-developed diesel engine! There is not much there to point us towards one vehicle or the other. Or is it?

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. 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, 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 results of an independent reasearch, while our visitors describe reliability of KIA with an average rating of 4.6, and models under the Hyundai badge with 4.5 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 these two vehicles rank it on average as 5.0 out of 5.

KIA is a bit more agile, reaching 100km/h in 0.3 seconds less than its competitor. In addition to that it accelerates all the way to 202 kilometers per hour, 1km/h more than the other car. When it comes to fuel economy things look pretty much the same for both cars, averaging around 4.7 liters of fuel per 100 kilometers (60 mpg), in combined cycle.

Hyundai 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 offering somewhat better performance, just enough to call it quicker. 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. 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™, out of 12.000+ vehicles we currently have in our database.