Many industry fleet owners already understand that propane autogas can generate better savings than other fuels. So, what happens when two industry trucks — one diesel, one propane autogas — go head to head in a savings comparison? This report examines that exact scenario, featuring two trucks operated by Delta Liquid Energy, a California propane company. Delta tracked and supplied the data for this comparison, and a detailed cost analysis was conducted.


To make a fair and informative evaluation, this analysis compares two similar trucks — one propane autogas and one diesel, with the same make and same model year.


Between 2014 and 2020, the company recorded two important data points:

  1. How much fuel the vehicles consumed during their lifecycle.
  2. How many miles they traveled within that timeframe.

This produced an accurate miles-per-gallon calculation for each vehicle. Records were also collected on the preventative maintenance and repairs of the engines and fuel systems.



Across the board, the propane autogas truck was better for the company’s bottom line than the diesel model, in terms of fuel and maintenance savings. The numbers below represent the results of the two vehicles on each side of the comparison.

These numbers validate the savings that propane industry fleets can achieve after switching to propane autogas. When multiplied across thousands of miles and an entire fleet of vehicles, the savings add up fast.


In order to accurately account for fluctuating fuel costs from year to year and market to market, an average price per gallon was established using national four-year average fuel prices of diesel and propane autogas. Fuel for the propane autogas vehicle cost the company less than fuel for the diesel vehicle. In fact, the fuel price per mile for propane autogas was less than half of that for diesel.


To compare maintenance costs, all invoices were collected for every preventative maintenance service as well as all engine and fuel system related repairs. This included diesel particulate matter filter replacements and diesel exhaust fluid, as well as propane fuel pump replacements.


The data collected on these two nearly identical vehicles offers propane industry fleet managers a clear reason to switch to propane autogas — it’s better for your bottom line, and for the industry.


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