A well-running and adequately maintained diesel engine should produce no visible smoke from the tailpipe. Modern diesel engines equipped with common-rail direct-injection technology have unlocked ...

Black smoke from the diesel fire could be seen rising high into the air. Multiple fire trucks responded to the scene. Firefighters said initially they were unable to put the fire out, because the ...

But the smoke test means something else for cars, especially those powered by diesel fuel ... and the numbers work out that a passing grade is anything greater than 53% transmission.