Re: thinking of getting a new air pump
The 450C actually has a much lower CFM rating, but it has a 100% duty cycle so it is better for filling tanks. I have the 450C with a tank in my K5, but after spending way too much time researching an air setup for the van (including powertanks, which I like best but can't justify the cost), I think I'll end up with with the 400P automatic. The 400P auto flows almost double what the 450c does and it automatically shuts off when you aren't using it. The 440p will fill a little faster still, but does not have the auto shut off feature and costs quite a bit more... GTDad, I think the 400p is probably the best value for occasional use.