[99LeCouch]

Quick, for our cars it makes a difference if you're neutral coasting or in-gear coasting. I do better neutral coasting downhill, unless there's a stop sign or another impediment to slow down for. I find I actually gain speed going down a steep enough hill, and gradual declines are enough to let me maintain speed. We don't have a fuel cut, it simply uses less. Where our air boxes are isn't much good for ram air. Sure does a good job drawing in ambient air. I'm blocking the frame opening off this winter for higher air temperatures and reduced knocking. My car doesn't like 15*F air...

For our cars, once they're warm idling in gear or in neutral uses the same amount of gas. 0.45 gph according to my ScanGauge.

Also, upgrading to lighter-weight ATF ought to make a difference. For us GM drivers, Dexron-VI has much better cold-flow properties than Dexron-III. And it's part-synthetic to meet the spec. I'm going to do it one of these days when I have nothing better to do.