Florida Grille Block?

[Loren]

I don't think you ever need to block the grille in FL to promote keeping the engine warm. (well, maybe if you do a lot of night driving in the winter months where the temp is down in the 40's at night... but even that is iffy) BUT, there may be benefit in blocking the grille for aerodynamics.

My opinion is this: The Yaris was designed to be drop-dead reliable in any weather, up to and including 120 degrees in the desert. The cooling system, and the airflow into it was designed to keep the car at operating temperature in that harsh environment.

In Florida, the highest summer temps are around 95, and in the other season (fall-winter-spring), the average is probably around 75-80. That's MUCH cooler than the extremes that the car was designed to handle, thus you should be able to get away with blocking SOME of the airflow to the radiator.

For my recent economy run, I taped the lower grille opening. I checked engine temp a few times and it was always a quite normal 180-182. No problem. I haven't pulled the tape yet, so I guess I'll leave it and do some more monitoring over the next couple weeks as temperatures rise. (it's rather cool here right now, highs in the low 70's)

By blocking the lower grille, at least half of the air that was entering the engine compartment and causing turbulence has been blocked. From what I've read on the hypermiling forums, this is likely a good thing.

I just used some heavy clear plastic packing tape to block mine. Nothing fancy, but it was intended to be temporary. Didn't even wash the car before I put it on. It's got bugs and autox cone marks under it!