No, just as long as the lowest possible voltage you can achieve will be completely stable. To be considered stable your comp should be run for a minimum of 24 hours using prime95 torture testing. Select the test that says "for maximum heat" or something along those lines.
I had my voltage set at 1.76, which was on the auto setting in BIOS. Everything ran perfect but my temps weren't where I wanted them so I changed it to 1.65 manually. I ran the Prime95 torture test for 24 hours and with no errors was running at 41 full load rather than 46 full load. Made quite a difference.