Without having taken into account the dimming function of the OEM rheostat, I swapped the bulbs in my dash instruments to bright white LEDs, the idea being to get brighter and sharper illumination on my instruments. I left incandescent bulbs in the places I wasn't looking to get brighter lights: turn signal indicators, brake indicator, charge indicator, HVAC controls. The dimmer allows full brightness BUT will dim the incandescent lights more than the LEDs. The change in light intensity in the LEDs is not very noticeable as you turn the dimmer control counterclockwise. Not a problem in my case since I did achieve what I wanted which was crisp white light from my instruments.