If you calculate it correctly it does.
This is an excerpt from FSC chart for the CSX railroad, which many trucking companies use as their reference.
As you can see, it starts with a base of 1.16/gal and then adds a % from there depending on the DOE US diesel price
Remember that fuel cost is only a portion of your per mile cost, and so when the fuel goes up, only that portion of your per mile increases.
DOE Low | DOE High | Percent FSC |
$1.160 | $1.199 | 0.00 |
$1.200 | $1.239 | 0.50 |
$1.240 | $1.279 | 1.00 |
$1.280 | $1.319 | 1.50 |
$1.320 | $1.359 | 2.00 |
$1.360 | $1.399 | 2.50 |
$1.400 | $1.439 | 3.00 |
$1.440 | $1.479 | 3.50 |
$1.480 | $1.519 | 4.00 |
$1.520 | $1.559 | 4.50 |
$1.560 | $1.599 | 5.00 |
$1.600 | $1.639 | 5.50 |
$1.640 | $1.679 | 6.00 |
$1.680 | $1.719 | 6.50 |
$1.720 | $1.759 | 7.00 |
$1.760 | $1.799 | 7.50 |
$1.800 | $1.839 | 8.00 |
$1.840 | $1.879 | 8.50 |
$1.880 | $1.919 | 9.00 |
$1.920 | $1.959 | 9.50 |
$1.960 | $1.999 | 10.00 |
$2.000 | $2.039 | 10.50 |
$2.040 | $2.079 | 11.00 |
$2.080 | $2.119 | 11.50 |
$2.120 | $2.159 | 12.00 |
$2.160 | $2.199 | 12.50 |
$2.200 | $2.239 | 13.00 |
$2.240 | $2.279 | 13.50 |
$2.280 | $2.319 | 14.00 |
$2.320 | $2.359 | 14.50 |
$2.360 | $2.399 | 15.00 |
$2.400 | $2.439 | 15.50 |
$2.440 | $2.479 | 16.00 |
$2.480 | $2.519 | 16.50 |
$2.520 | $2.559 | 17.00 |
$2.560 | $2.599 | 17.50 |
$2.600 | $2.639 | 18.00 |
$2.640 | $2.679 | 18.50 |
$2.680 | $2.719 | 19.00 |
$2.720 | $2.759 | 19.50 |
$2.760 | $2.799 | 20.00 |
$2.800 | $2.839 | 20.50 |
$2.840 | $2.879 | 21.00 |
$2.880 | $2.919 | 21.50 |
$2.920 | $2.959 | 22.00 |
$2.960 | $2.999 | 22.50 |
$3.000 | $3.039 | 23.00 |
$3.040 | $3.079 | 23.50 |
$3.080 | $3.119 | 24.00 |
$3.120 | $3.159 | 24.50 |
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