Sell or keep BA xr6

Currently have my xr6 on the market. It’s a good car, owned by my grandmother and then passed to me 3 years ago. Has done 214,000 k’s. I’m 21 and my main issue is the fuel consumption. I’d get 420 k’s a tank and it would burn me dry as a uni student (still 1.5 years left of the degree). I have mates with 4 cylinder who tell me they get 1000k’s a tank. I was planing on selling it for 5-6k and buying a more economical car, preferably a 2nd gen crv as I have a JetSki I would like to tow. From a financial perspective would I be better off switching to something more economical or would I be running the risk of getting a ‘cheap car’?