Increase efficiency with high-pass filters?

Would adding a pair of 1st-order passive high-pass (85Hz) in-line filters to my main speakers (rated -3db@55Hz; TMM; M's are 6"; ported) gain some efficiency for me? My goal is to possibly use a lower powered amp. I also use a pair of self-powered subs to fill in the bottem end.
And if so, approx. how much? At least 3db?
Sorry, but you wouldn't gain any efficiency.

If you're talking about a filter that comes before the amplifier, you'd gain about 1 dB of amplifier headroom by relieving it of having to reproduce the bass region at full power. If the filter comes after the amplifier, then it depends on the amplifier type but at most you'd gain about 1 dB of headroom.