For the small voltage drop (from at battery reading to gauge hooked to light in cluster) you can just adjust the gauge to be accurate. I hooked up my gauge and used a multimeter on the battery and noticed only a small difference (like most people have noted). If you look on the back of the gauge there will be a small silver circle with a Philips looking pattern. turn this counter clockwise to up the reading and clockwise to turn it down a bit. I simply adjusted till the readings match. Now I have the same reading at my battery as I do in the cluster. This is a sweet mod by the way. Looks awesome when completed!