I would have to put in my vote for the old dodge slant 6.
I drove a ford escort with the 1.8 mazda I4 engine for over 200K frequently towing motorcycle trailers with it - never had any problems.
The most impressive engine I've seen lately would have to be a BMW. A buddy of mine has been driving the same old 1985 BMW 325e since the car was new. It is a 2.5L I6. The odometer stopped working at 380K that was before he moved to the mojave desert about 6 years ago. He works in el segundo - about a 2 hour trip each way. he has no idea how many miles are really on the car but the automatic transmission has never been apart, and the valve cover has only been removed for valve adjustments. He drives the car like a maniac, but the engine was low compression from the factory, only makes about 120hp, and redlines below 5K. He has done a lot of work to the car to keep it running, but nothing to the engine or tranny. He has no plans to replace it any time soon. He uses mobil1 oil in the engine, and dino ATF. The Air conditioner even still works, although the power windows have broken many times.
I drove a ford escort with the 1.8 mazda I4 engine for over 200K frequently towing motorcycle trailers with it - never had any problems.
The most impressive engine I've seen lately would have to be a BMW. A buddy of mine has been driving the same old 1985 BMW 325e since the car was new. It is a 2.5L I6. The odometer stopped working at 380K that was before he moved to the mojave desert about 6 years ago. He works in el segundo - about a 2 hour trip each way. he has no idea how many miles are really on the car but the automatic transmission has never been apart, and the valve cover has only been removed for valve adjustments. He drives the car like a maniac, but the engine was low compression from the factory, only makes about 120hp, and redlines below 5K. He has done a lot of work to the car to keep it running, but nothing to the engine or tranny. He has no plans to replace it any time soon. He uses mobil1 oil in the engine, and dino ATF. The Air conditioner even still works, although the power windows have broken many times.