Toyota had the million mile V8 that they put in everything and the 1 and 2 JZ engine was pretty bulletproof if you didn’t modify it to 1000hp.
Does BMW have a bullet proof engine? Or bulletproof era of cars with little to zero problems and can last at least 300k miles?
If you’re talking mileage maker engines, then the M20 and M5x motors. There’s several examples of those bumbling around with 300k+ miles, probably driven by grannies