DaGnoma exceeding expectations...
 

I realize it isn't much compared to some of you guys, but I'm excited about the improvements that I have made with my Sonoma. She has the 4.3L V6 with a 5-speed and 3.08 final drive. EPA rating of 16 combined, yet on this tank so far I have kept an average of 28.6 MPG! 78% over EPA with no aero mods whatsoever, just driving by instant MPG. I don't have a Scangauge yet, but I do have an ODB2-USB adapter and a laptop. The software appears to be bang-on with the speedo and fuel - when I arrived at work this morning I had 243 miles on the trip odo with slightly over a half tank. At this rate, I'm estimating 470 miles on this tank or an entire week of gas for my commute at about 80 miles roundtrip. Previously, I'd have to fill up Monday morning and again on Thursday afternoon. Now for that air dam and half-tonneau... 30+ MPG here I come!

That's awesome! You'll get higher numbers, but nothing's ever as dramatic as your first tankful.

That's a great improvement over the EPA of 15 city 20 hwy.
28.6 is a 30% increase over the hwy rating, which is fantastic,good driving.

Congrats on the 28 mpg thats fantastic. With some aero mods I could see you in 35 - dare I say 40 mpg.

Thanks, guys. I am starting to suspect the "highway gear" axle was the smartest option that I picked on this truck. 185k miles and still running strong. And tonight I discovered that I had about ten feet of landscape edging in the shed leftover from another project...

The truck needs some serious aero mods. I have noticed that it requires a rather steep downhill grade to coast and maintain highway speed. 60mph seems to be my "stall" speed even on slight grades. I'm still running 235/60R16 tires as well, not sure if a smaller patch on the road would help as well.

Roundtrip average since yesterday... drumroll... 29.3! I'm coasting more, and managed to tuck in behind a tractor-trailer for most of my trip on the I-240 loop. 30MPG so close I can taste it! lol

Just posted my tank average, didn't quite make it to 28mpg but still logged a respectable 27.1mpg! Had I driven the entire tank with the laptop, I probably would have hit it.

When you get the a airdam on there I could see you getting 30 mpg.

I had already planned the air dam project for this weekend. ;)

Also I ordered new spark plugs, wire set, and all three oxygen sensors (OE, not the uni junk) from Rock Auto. I figure after over 11 years and 180k miles, it's time for new sensors. The fun part should be getting them off. I'll drag out the welder and fix a little exhaust leak while I'm under there... also a fine time to scope out my belly pan.