Last night while roaming around Pep Boys, AutoZone, and a few other auto parts stores looking for the last of the Mobil 1 0W-20 (found 2 cases), I started looking at the flexible preheat ducts.

The warm air mod has been around for awhile and was suggested by a few Insight owners to boost the MPG's, especially in this cooler weather.

At first I was cautious about doing the mod, the car is not even a week old yet. Less then 600 miles on it! Still on the first tank of gas.

I got beyond the worry and purchased two 16" lengths of 2" metal duct (used on older cars, from the exhaust manifold to the air filter, for preheat). One length wouldn't be long enough, so I used some metal foil tape that was leftover from a home insulation project to tape the two sections together.

After studying the routing under the hood, I went with the tried and true method of snaking the flex duct around and under the 12 volt battery tray and on to the upper catalytic converter. Kept it away from any cables and wires by using a single tie-wrap to secure it loosely to a heater hose that was nearby. It has about a three-quarter inch gap between the end of the duct and the converter heat shield. Plenty of space to pull air.

The air filter end was easy to do, just took the hose clamp off with my fingers, pulled the stock rubber tube off, and re-connected the new hose using the same clamp. The stock hose is just set off to the side, but still supported.

The temperature this morning was 41 degrees for the drive in to work.
It appeared to stay in lean burn slightly longer.
Hard to tell any increase in mileage.
It will take more driving to see the full effect and me learning to use the car better.
My other concern is to know when to pull the warm-air hose off and go back to the stock set up.
How would I tell without some form of intake temperature readout?