Thumper and I own an earthwork and asphalt paving company in Phoenix - we would be considered an upper middle to low high volume subcontractor in the area. I just asked her what our fuel bills per month were a year ago, and what they are now. Wow!
Including red diesel (for the yellow iron), white diesel (for the over-the-road trucks) and gas for the pickups:
Last year: +/- $ 50K per month
This year: +/- $ 75K per month
Allowing for a 5% increase in volume (sales) of $ 2,500 per month, our net increase in fuel costs is $ 20K per month from last year at this time. This increase is comparatively equivalent to last year's sales in the fall months and this year's.
Add to that, the fuel companies' terms are net 15 days for payment, and we get paid (on average) 60-90 days after we bill the general contractors (less 10% retention, which the general contractors pay after they receive final payment - which, if you're paving a WalMart, can be one to two YEARS after we complete the project).
We're in the wrong business.