Cummins engines have more than just a deep diesel rumble. They have a signature sound that sets them apart. But what causes ...

While major motorcycle manufacturers produce a wide range of impressive mainstream bikes, the custom-built world of motorcycles is far stranger, with some examples that seem to break all the rules.

Black exhaust smoke, tractor-like engine noises, and sluggish performance: all things that were associated with diesel engines. And I say “were” because they’re mostly a thing of the past. Modern ...