It wouldn't make much difference because of the fuel surcharge rule applied to shipping bills.
How it works:
Base fuel price is assumed to be $1.25.
Base fuel mileage is assumed to be 6 MPG.
Fuel rises to, say, $3.65. The $2.40 difference is divided by 6. 40 cents per mile is added to the bill as a fuel surcharge.
You can see what CLNE is up against. No matter what happens to the price of diesel, the shipper pays. Everyone assumes that the trucker pays, and there is a cost to the fuel. But he doesn't pay NEAR what everyone thinks.
When shippers insist that their truckers use LNG, everything will change. Then, the diesel trucker will be forced to use LNG in order to stay in business.
your analysis ignores the fact that a trucker running on nat gas would not need to add a surcharge. A nat gas operator could bid on a haul based on flat rate pricing, without a surcharge. That would provide certainty for the shipper. and a lower rate overall......