Used car……

Im after some advice, I’m looking to buy a used car, I really like the bmw x6 3ltr diesel which is around the £6000 area. But unfortunately due to my travel distance from my home to work etc I don’t travel many miles. I’ve been told that I need to travel a fair few miles for a diesel car but from my home to work is about 5 miles. So with that I mind is there a similar car (prefer a suv style car) to a bmw x6 that is petrol.