left the eco flaps on the truck when I turned it in to Schneider. Planned on just getting new ones for my new truck which is now 3 years old and still had the solid mud flaps on it until today.
So, I was at the Iowa80 today (which has zero paid parking now), and after a shower, decided this would be a good day to update the mudflaps. Only this time, I had double the cost as I had to purchase a set for the trailer as well.
Iowa80 no longer sells eco flaps. They now sell their competitor, Aeroflaps. Different design, still vented, still wanted them, so still bought them.
15 minutes into this ordeal, I was wishing I had replaced the mudflaps on my tractor 3 years ago and wishing I had waited on the shower. I say 15 minutes, because I started with the trailer and had that done in less than 10 minutes. The tractor was another story. After lots of work, got the first bolt out. After lots more work, twisted the 2nd bold in half. Back to the sidebox for more wd40 and this time, the assistance of a wire brush as well. Lots more work later, all 8 bolts were removed, mudflaps replaced, and 7 bolts reinstalled. Only other casualty was one very bloody knuckle.
How much to vented mudflaps help? not sure. Mesilla Valley tested them with and without sideskirts on their trailers, I think it was a very short test and they achieved a .7% gain (.06mpg). minimal fuel economy gain on their test, but they have an already very aerodynamic setup. Others that I can no longer find had better gains on their testing.
As for me, I rolled across 80 in Iowa today, just under 80k gross, at 7.9mpg (60mph). On flat land, across illinois, I was running the same mpg this morning. So, I ultimately achieved the same mpg on the rolling hills through Iowa as I was able to get from my starting spot in Indiana this morning to the Iowa80.
The thing I liked about the mudflaps on my previous truck, is the instant reduction in roadspray. if nothing else, they are worth the money for that alone. Doesn't help me so much as it helps those passing me on wet nasty roads. If they can see better, they have less chance of hitting me.