FWIW, I replaced the bulbs in our original fixtures with brighter LED bulbs... and that was a marginal improvement.
But then I added a 5-meter flexible "rope" of bright white LEDs at one end of the engine room... just tied it into the existing circuit... and that made even more difference.
I still have capacity on that 10-amp circuit, so I intend to add another "rope" of LEDs at the other end of the engine room... next time I get a round tuit. Prob'ly this spring.
-Chris