Please can you help with the following decision. I am looking to buy a Mercedes W211 E-Class V6-engined saloon. I know the post-2006 facelift cars are the best ones, but should I choose petrol or diesel?

I do around 18k a year, but I have avoided diesels in the past because of the high cost of replacing components, but you list in your website that the petrol V6 engines have a problem with the timing chain sprockets failing and costing £4000 to repair. Could this be mitigated by an aftermarket warranty? If not, is a diesel worth considering instead? They seem to cost more to buy used than petrol cars too.