Hey all,
Just figured I'd put my 2 cents in on this subject.
I've thought about adding propane to my Ram for awhile now, but I thought I'd test it on a company vehicle first. Here's what I've found so far.
I just put a propane injection system on a 2000 Kenworth T300 propane delivery truck. The truck has about 160,000 miles on it. It has a Cat motor and an Allison Auto. Fully loaded the truck weighs around 28,000 lbs.
I had one of my drivers do a test run to determine if there is a noticeable difference in power and fuel mileage. He made two identical trips of 29.5 miles. One with propane and one without. The driver said he used 2.1 gallons of diesel with propane (and .9 gallons of propane) and 3.6 gallons of diesel when he ran without propane. That figures to 14 mpg with propane and 8 without. That's a pretty big difference. I'm going to do some more testing to prove the numbers. I do know from prior experience the truck sees about 6.5 mpg average during it's everyday stop and go delivery driving.
As far as power goes, the difference between propane and no propane is definitely noticeable. It scoots pretty good for a big truck.

 

Yes, keep us posted. I am interested in one for the Megacab and the Freightliner!

 

propane helps in the burning of diesel, also since itraises the BTU factor ofdiesel you'll get more power.

propane injection will help with fuel mileage, however there is a cost to benifit ratio that many of us here will never see returns on.

 

When burning two fuels at the same time,
doesn't MPG fail to be important any more?

Shouldn't the cost of the diesel and propane be added together
and a cost in dollars per mile calculated?

When burning propane on the highway
you are supposed to 'volunteer' to the state and federal governments that you are using it this way, and send in extra road tax, typically about $0.49 per gallon of propane burned.

 

Hank-
You're completely right. You are using two fuels. Here in southern Ohio the cheapest diesel I know of is 2.799/gallon. That's what I paid for the test truck. My propane right now is $1.999/gallon + tax (6.5% of total sale amount). Total cost propane + diesel for my test was $8.00. Total cost running only diesel was $10.08.
And yes, you're also right about paying road tax. Here in Ohio it's the federal 16 cents + Ohio 28 cents = 44 cents total. However, propane is considered an alternative (clean burning) fuel by the federal government, so you can actually take a tax credit of 50 cents per gallon used. It nets out to no taxes if it's used as a motor fuel and your state's road tax + fed tax of 16 cents per gallon = less than 50 cents. That is assuming you report it to begin with.