Yes. The market is swamped with diesels as, a few years ago, there were lots of incentives to buy diesel cars. These no longer exist and people have realised that diesel cars don't suit everyone - so used prices have dropped. You need to decide whether a petrol or diesel car suits your use best. If you cover a lot of miles (particularly on the motorway) and/or need to tow a heavy trailer or caravan, a diesel X3 is the best option. For lower annual mileages (less than 12k a year) or regular short journeys, you should buy a petrol model.