A Note About "Plus" Bulbs (H1, H3, H4) - Daniel Stern
"Plus+" bulbs (+50, +80, +110, etc) are standard-wattage items with higher filament luminence and tighter filament focus. They give better headlight performance than standard bulbs—longer seeing distance and broader beam coverage—with an attendant shorter bulb lifespan. They have totally or mostly colorless clear glass so all the filament's light reaches the road (some of these have a blue band near the tip; it does not reduce light reaching the road because of its placement). The small number of reputable makers in the world differ a little in how they test and label their bulbs—the bulbs called "+110" by Osram, "+120" by Tungsram, and "+130" by Philips are substantially alike as a class, though depending on the bulb type there may be a reason to prefer one over another;