My cig lighter outlet is run on 8 gauge wire. I made the jumper to go to my riding lawnmower. The jumper wire itself is probably 10 gauge, and is roughly the same size as the battery cables on the rider. Usually it just needs an 'assist', or boost... Depends if i have left its lights on, or was using it to run a tire pump etc.
Many companies make an 'assist' cable for lighter to lighter connections, as well as booster boxes that connect to the lighter. In most cases though, you have to realize that there is only a 20 - 25 amp fuse on that circuit.. and that is the limit of the assist you can get by with without a fuse failure. If your lucky, it is on a breaker like a power window, etc.
Soundguy
red]Are cigarette lighter sockets heavy enough for jump starting a vehicle?"
No. You can trickle charge with a cigarette lighter plug but it will never hold up to the amps needed for a jump start.