Your cars gas tank is very flat on the bottom and we were told at school when those cars were first introduced that if one runs that tank dry, it then takes 6 gallons of gas to get the pump primed and working again (due to the shape/design of the tank and pickup). If that's true and you run it dry, consider that it'll take more than one trip back with a 5 gallon gas can just to restart it. IMHO, it's something you wouldn't really want to try.

It also baffles me why Volvo owners do that test often, testing their low fuel lights? I don't ever do that with my cars, when it's getting low I just stop and fill it up. My $.02 on that.