"A smooth road is more energy efficient, now that you mention it."
Some years ago GM built an experimental, hydraulic active suspension for a (big) Blazer. When going along at higher speeds off-road it allegedly consumed ~40 hp.
42 posted on 01/02/2009 9:04:04 AM PST by Paladin2
(No, pundits strongly believe that the proper solution is more dilution.)