I am not sure about Petrol Engines. However diesels at least they are typically tuned to run anywhere and on differing grades of fuel. However if you get your d

I am not sure about Petrol Engines. However diesels at least they are typically tuned to run anywhere and on differing grades of fuel. However if you get your diesel car remapped you get better power and mileage out of car. I had mine remapped an extra 20hp (on a 95HP car) and the fuel economy improved quite a bit. As for engines that last 40 years and 750,000. If you look after Diesel engines they can get to 500,000 or more. However people don't once the car gets over like 100,000 miles. Servicing costs typically more than the car is worth.