How many miles can a BMW engine go?

They can go a very long ways but how long this engine will go depends on how it was driven and how well it was maintained.

The lubricant parts of engine may go many many miles, over five six hundred thousand miles depending how it is maintained. if it is religiously maintained; going to BMW dealer for service at least twice a year. When in BMW dealership for service; the service writer there recommends and replaces many accessory parts such as starter, alternator, sensors, gaskets and so on. therefore, the accessories perform well and the engine moving along for that many miles.