[FastPlastic]

I think this depends a lot on the vehicle. In your case with the low GPH numbers you see at idle it may take a while for the savings to really add up(with luck it covers the new starter and then some). In the case of my Jeep I run about 0.79GPH idle. So it's sucking the gas like none other. So I have found short trips across town(about 5-6miles) it pushes the trip avg up 1-2MPG's if I turn it off at a 20-30second light.

I'm sure others may say it's not worth it. Claim it doesn't counter-act the cost of a new starter. But there are a lot of factors to take in to account, like the fact that in your case you spent 17:30 with the engine off, so the engine will last longer. If you want to get in to the nitty gritty, think about the money you just saved, how much intrest will that earn if you put it in the bank now to cover the new starter down the road?