[MetroMPG]

I think you'll find that there's no easy solution to pre-warming an engine without access to AC power for a block/coolant heater. Or at least nobody has figured one out yet.

RH77 had been wondering the same thing because he often left his car parked at the airport for work trips, so he faced an icy cold engine on his return. Big downer for someone used to using a block heater @ home.

Another point to consider is that it's not just the engine but the entire drivetrain that benefits from higher ambient temps later in the day when you're seeing better fuel economy: your tire pressures will be higher; warmer rubber = less rolling resistance; lubricants in the wheel bearings is less viscous; transaxle oil is less viscous...