The question of whether or not to keep forcing more gas into your tank after the pump clicks off for the first time probably comes down the issue of where you will be driving that vehicle. If I was about to drive across the trackless wastes of the Atacama Desert, I would probably try to force as much gas into the tank as was possible, simply because it would be–literally–a survival issue.
On the other hand, if I was driving in the more settled areas of the lower 48 states, I would err on the side of caution and do exactly what most Owner’s Manuals state regarding this issue, namely…Do not continue to fill the tank after the gas pump clicks off for the first time.
Why do I say that? Because I have observed the outcome of doing the click-click-click routine with the gas nozzle.
I repeatedly warned a friend of mine about this practice, but he ignored me. A couple of months later, when he began to have problems fueling his Toyota Highlander (circa 1999), it turned out that the carbon canister in his Evaporative Emissions System had been saturated with liquid gasoline, rather than the gasoline vapor that it was designed to deal with.
The bottom line is that he wound up paying over $300 for replacement of that carbon canister, which was a totally avoidable expense if he had just followed the advice provided by both his Owner’s Manual and by me. In case you were wondering, he never has the occasion to drive more than…perhaps…10 miles from a gas station.
Repair costs that were totally avoidable…and that were the result of totally foolish behavior.