There is no alternative for heavy transport and truck diesels. They are now fitted with diesel particulate filters and Nox traps that routinely have to be cleaned or replaced every 80,000 miles or so. Some heavy trucks have been converted to CNG in the Far East, but this involves carrying a virtual bomb rack of CNG containers. However, there is no need for cars to have diesel engines and over a seven year life of a new car an EU6 diesel engine will require so many expensive component replacements that its total running costs will usually exceed those of a petrol engined car driven over the same period.