04 civic mod questions

[Hayseed]

Hey gang
I have been floating through the forum for a while and am looking to make
some mods to my wife’s 2004 Honda civic 4door.

She travels 114 miles round trip a day.

I am hoping to find someone that has worked one before and would be willing to share what they have done but all suggestions would be appreciated.

I am thinking a full grill block, a front air dam, side skirts, solid hub caps, rear wheel covers and take off any antenna as well as try to move the mirrors in the car.

I am concerned with the grill block and the air dam as will these prevent the radiator from doing its job? From experience how much should I expect to pick up in terms of FE?
Thanks

[Daox]

Welcome to the site.

What kind of mileage is she getting right now? Driving techniques are really the first thing to look at. You'll gain more there than any mod will give you.

If you are going to be doing grill blocks in the summer you really need to get yourself a scangauge or other accurate way of measuring coolant temperature. The blocks will prevent the radiator from doing its job to some extent and overheating is a possibility.

The antenna is not worth removing for aerodynamic reasons. You won't even see a 1% improvement in aerodynamics, much less mileage.

[PaleMelanesian]

I second the vote for a Scangauge. Easiest and most effective mod. It'll tell you how to improve your driving technique, and tell you if any mods are working, and help you monitor things like engine temperature.

[cookie96civic]

Without a scanguage, will my thermostat display (stock) still read accurately? With upper and lower blocks, is there enough air from under the car to cool it?

[Sandy]

I too have an '04 civic 4-door sedan.
Before the ScanGauge and driving techniques change I could only peak at 38 mpg in the summer and generally around 32 - 35 yearly average.
Since the ScanGauge and the lessons learned, it's up to 41 to 42 mpg regularly.
The upper grill block didn't help much, but the lower did,
but it caused me too much concern here in the summer heat.
I (actually another car) took off my drivers side mirror and it's been replaced by a convex mirror mounted inside.