I dunno, I've tried just putting higher wattage bulbs in my Subaru's headlights and the difference was really hard to tell if at all.
Without relays most wiring harnesses will not supply enough extra current in order to supply much extra light. Whatever extra current does flow goes into heating the harness instead of the filament. A voltmeter is an excellent eye-opener, just hook it between the battery positive terminal and the headlight pin. My wife's SL had 1.2V of voltage drop to the high beams when stock. After the relay operation, _and_ doubling the bulb wattage, the drop was only 0.3V. Significant. Very significant. -- Jim
