changing air filter in 97 cheyenne

I drive a 97 chevy1500 cheyenne v8 5.7L. I posted a reply last week about poor gas mileage. I had all-terrain liberator tires on my truck before i got mud tires. They were 235/75 R15 so i assume they are about 29 inches. The new buckshot mudders are 31x10.5 so they are bigger and heavier. I'm gettin very poor gas mileage now with the new tires and was wondering what I need to do. I changed my air filter today and when I took the black case off where the air filter goes, it looked like a birds nest. There were leaves, dust, hay, dirt, flies, etc packed in there tighter than tobacco in a ciggarette. I washed it out as best I could and took all the junk out and put a brand new air filter in. I was wondering if that was normal or not and if this will help my gas mileage out any. Thanks for any replies.

It should definately help your mileage. It's not uncommon for the air filter to become clogged up depending upon the operating enviroment

Bigger tires=less miles on the odometer. In other words, say you drive 60 "actual" miles on stock tires, your odometer would show 60 miles, as it is calibrated for the stock tires. So you put some big "mothers" on. You drive the same "actual" 60 miles but your odometer only shows 55 miles. Not only do the bigger tires show less mileage but you're going faster than the speedo reads and your performance has decresed because the bigger tires have changed the gear ratio from stock(say 3.73 to 3.50)(just a guess). Bottom line is your mileage may not have decreased it's just that you need to get the speedo recalibrated to match the size of your tires. Dealer can do that=$$ or you can get a hand held tuner and do it that way=$$. Or you can drive measured miles and figure out what your speedo difference is and recalculate your MPG. Getting the birds nest out of the air cleaner box should help too. Good Luck.........Steve

They were 235/75 R15 so i assume they are about 29 inches. The new buckshot mudders are 31x10.5 so they are bigger and heavier.

Buckshot are nice tires.