Chairman Kaga

So I had to come home yesterday. Chicago to Arkansas. After sedating me and leashing me into the seat of the car, we hit the road. We'd planned to stop for gas around every 300 miles, regardless of where the needle was. Here were the conditions- roughly 72 mph through most of Illinois (don't have a radar detector at the moment, although there was about an 80-90 mile stretch of 90-100 mph between I80 and Champaign), cruise on, AC off, moonroof open, windows cracked.
The further south we got, the worse the gas mileage got. We WERE getting 32 mpg up north. Once we hit Missouri, especially Arkansas, it dropped considerably. Between the last gas stop and home we got 26 mpg (by the way, I drove 15 hours contintously in a GSR. Somebody give me a damn cookie, please! ) . The only real difference was temp (not much, maybe 5 or six degrees, since it was night by the time we hit the southland) and humidity (dry and mild up north, a 500 pound pig in Arkansas).
My guestion, how much does humidity affect your gas mileage? It's kind of depressing to think I'm losing that much. Also, will buildup of water in the engine lead to hydro lock over time? Do I need to get some water remover stuff? What should I be aware of, constantly driving around in 90% humidity 9 months out of the year?
Just wondering. I have to go icy-hot my *** now...

H23 Power

i dunno 26 mpg on a highway trip is pretty low no matter what the weather is like...

but 32 is pretty good, that is a big difference.

i remember in my 88 accord coming from IL to TX there was a stretch that was almost down hill the whole time...we got 35 mpg in that period...about 30 the rest of the way so maybe you were going up hill a lot

Chairman Kaga

I guess I should add I have NEVER gotten better than 30 mpg under any conditions.
I'm probably safe in assuming a few degrees difference in ambient temp wouldn't make a big difference. Isn't it like 10 degrees + 1 hp? We're talking maybe 7 degrees difference.
Also to clarify, it was definitely windier up north, although we hit some rain just north of the MO border.
Also, last time I drove to Dallas, I got the same mileage as I did on the second half of this trip (about 26 mpg), except I had the AC cranked! Recirc and full fan the whole trip.
I'm just wondering to what degree humidity adversely affects fuel efficiency, and if there is any way of drying out the air before it hits the TB.
Thanx

Chairman Kaga

One more thing. I haven't been able to check a topographic map to see what the changes in elevation are. It's pretty flat for most of the trip, though.