2016 BMW X3 Pricing and Specs

Your fuel consumption is way off the claimed consumption figures released by BMW. The company claims the X3 20i should get on average 7.3L/100km, 6.2L/100km on the highway, and 9.2L/100km in city driving. You have to allow for some variation on those numbers due to individual driving conditions, but to be so far out suggests there is something wrong with your car. I wouldn't expect it to reduce enough to get even close to those numbers simply by driving it. Have it checked by your BMW dealer.

You need to get to the bottom of what caused the failure in your engine. It is all very well to assume it was caused by the timing chain wearing and stretching, but until you actually establish that as the cause you won't get anywhere with the carmaker. Have an experienced engineer inspect the damage and if they believe it is caused by the timing chain failure you have something you can take to BMW to argue your case for compensation. You also then have the option of going to consumer affairs to get their help.

The X3 would be fine but you should also - perhaps surprisingly - consider a Volvo XC60 which I rate as slightly better than the BMW as a secondhand choice.