I had a 1954 Bentley with 140k miles on it. I checked the net for prices. Almost every car I saw with over 150k miles on it had either a new or rebuilt engine. I asked the local Bently expert why should a car that is reputed to go on nearly for ever should have to have a new engine at 150k. He said that the older cars never really went on for ever. That because of the poor quality materials used, esp. in the early after war cars, that they were not very reliable. They lasted a long time in England simply because most of them were never driven that much or that fast. Here in the States they were hammered for long distances at high speeds and basically just couldn't take the punishment. The new Bentlys and RRs are a different matter