I've had it with this horrible Gas Mileage! Idea's?

[DK]

I posted a couple of months ago that my mileage dropped from 16.5 to 13.5 immediately after I had my 30,000 service at Sierra. Today I took the VX in for them to check things like the 02 sensor.

Here's what found:''Diag fuel ratio in specs, 025 sensor in specs...no problem found - performed scan tool diag -- found no DTCS -- all fuel trims in spec -- fuel ratio is right on -- 02 sensors working correctly"

Looks pretty thorough to me. No problems identified.
Am I correct in assuming that if some of the things mentioned above -- pinched lines, etc. -- were the cause this would have showed up in the testing?

So other than brake drag or flat tires, what else could it be?

Question: if the brakes were dragging enough to reduce my mileage that much would I not notice excessive heat and some kind of burning smell?

[Numba1goalie]

Update: When i first started this thread I was fresh with a new tank of gas and apparently the VX heard my growling and got 355 miles to the tank.

Now with a new fill up, I'm at half tank and only have 134 mile sont he odemeter. Here we go again I guess.

I am ordering a new intake manifold gasket soon along with some other things.