The engine proved to be unreliable and lacking in power.

The engine operated until about 1848 but proved to be too heavy for the line and was never entirely successful.

The engine proved its worth when it started at the first try.

The engine proved to be very reliable apart from this issue.

The engine later proved to be mockup made of wood.

The engine proved to be a disappointment by not performing as expected.

Still, both engines proved to costly to finance with the available budgets.

This engine would not prove popular in the face of new V-6 engine options, though.

Over the years, the engine has proved both versatile and durable.

The truck's engine did not become available until September and proved expensive to produce.