KIA Sorento and Hyundai Santa fe are more or less same. Both vehicles are worth buying. What ever You buy. Check the conditions and after that maintain properly.
I am using a Santa Fe 2013 model and so far so good.
It is a good car. I have used a fd 1 for 5 years and had no any major issues. As Supra said , go for a well maintained car and have a good driving pleasure. Wish you all the best.
My wife one does only 11.5 km/l at moderate traffic though agent says it will improve after the first service yet to experience. Other than that it is a decent car for the price.
If the culprit is valve, You may clean it and try. If problem exists, You have to change the valve. It s bit expensive. I got my one changed at the agent(FD1) and cost me 25000 Rs. about a year a go.