Old, naturally-aspirated diesels would run forever, but they were heavy with iron blocks, and developed very low horsepower. As a result, they were very understressed. Today’s lightweight, high horsepower, turbocharged direct injection diesels are a very different beast. In the boating world, I’ve read one article where the author basically said you could get only so much horsepower-hours out of an engine — a low power diesel would last a long time, but not develop a lot of peak horsepower. In contrast, high power turbo-diesels develop high horsepower, but for a much shorter period of time — that is, high horsepower diesels don’t last anywhere near as long as the old, understressed, naturally-aspirated diesels. In addition, the current emissions regulations significantly increase the complexity, cost, and fuel consumption of Diesel engines.
While I would carefully consider a diesel LC, if it were available in the US, the reality is that it just won’t happen. The cost to federalize a new drivetrain is enormous. Toyota can justify multiple drivetrains for vehicles with large production runs (like the Camry) because the engineering cost is amortized across hundereds of thousands of units. But Toyota only sells a few thousand LCs per year, so the cost to federalize a diesel drivetrain just doesn’t make financial sense.
While I would carefully consider a diesel LC, if it were available in the US, the reality is that it just won’t happen. The cost to federalize a new drivetrain is enormous. Toyota can justify multiple drivetrains for vehicles with large production runs (like the Camry) because the engineering cost is amortized across hundereds of thousands of units. But Toyota only sells a few thousand LCs per year, so the cost to federalize a diesel drivetrain just doesn’t make financial sense.