(quoted from post at 04:08:42 07/03/13) This is as good a place as any to jump in. Agree, it all depends on the useage.
Look at all those yellowish Schwan's ice cream trucks. Freezer bodies are heavy. Run heavy a couple miles, then shut down to make sales calls. Then run again. Low daily mileage. Up until just the last couple years, if it said GMC on the front, it was a 454 running on propane. Not sure how some of the newer rigs are powered.
One place I worked some years back had gas big rigs. Boss penciled it out, needed 75000 miles to make diesels pay. Problem was we needed heavy frame/axles etc to handle the weight, but longest haul was 2 miles or less, then lots of dock time, 40 miles a day tops for 1 rig that ran double shift, 5 am to 10 pm. Some only ran 15-20 miles a day. At that rate, it would take 8, & up to 15 years to make diesel cost efficient.
Willie, you have it right. The trucking companies purchase based on life cycle cost factoring ALL costs.
In a nutshell, work it hard, run high miles, diesel gives lower lifetime cost. But lower mileage, lighter loads, lower initial cost, gas costs less over a vehicle's lifetime.
That's my opinion,& I'm sticking to it.
Willie