[jray3]

Anyone run numbers on the payback for an oversize vacuum reservoir, perhaps even one that gets pumped down really low while plugged in, with a regulator to ensure that the booster sees normal vacuum levels? Basically the question is which is the better investment- a pound of reservoir, or a pound of battery?

Electric pumps make 21"+ of vacuum easy, though 14" is often enough for the brake booster.

Years ago I proved that for EVs, a hot water bladder delivers more heat per lb than a supplemental battery for winter heat, and am wondering if an upsized reservoir that gets pumped down while still plugged into the house could also be worthwhile...