The tougher you make it to steal the harder they will attempt taking what they want, or do more damage somewhere else because they didn't get what they wanted, unless your dealing with incredibly stupid thieves. As for arming with alarms and camera's and whatever else, odds are if they are somewhat intelligent they'll outwit you anyhow. If you build a better mouse trap you'll end up with smarter mice, it might take a while but odds are, since they have nothing else worthwhile to do they'll figure out how to beat you in the end, also chances are your being watched anyhow so the day you don't take the battery home is the night they'll take the battery. As for fuel, maybe don't fill it up every morning or evening so its low at the end of the day, 10 or 20 gallons might not be worth their time, someone else leaves the tank full every night, I always fuel in the morning and most know it, since I've done it that way I haven't lost any fuel, before I lost fuel all the time, as for condensation, at 3-4 bucks a gallon I can drain some water or change filters more often and be paid very well to do it from a few lost or not lost tanks of fuel.
I guess its just how you look at things, I try not to leave anything worth while for an easy steal, like fuel or new batteries, I put the new ones in my trucks and things that go home at night I've also switched most of my machines over the run off the same battery size and type, thread top semi batteries, also makes to the average moron pretty worthless to steal, since he can't easily pawn or sell them to any idiot on the street, like either side or top post terminal batteries. It makes his potential buyers pretty limited.
