Truck Conversion & Toterhome Community - View Single Post

hot rod · 03-18-2011, 06:07 PM

Eskimo-

I'll have to check into the rating on the 6500. I know my 8.1 in my 2001 3500 was the first year for that motor in the duallies, and is not rated as high as the newer 8.1's, I think 290hp off the top of my head.

The power level of the propane vs. gas does not bother me, propane was our family business and literally the first thing I ever drove was a Wheel Horse with a bbq tank on the back, and have run everything you can think of on propane, from cars to mdt's to race cars. It's 108 octane and tuned properly can outperform gasoline. The problem is nobody knows how to tune properly. You are correct on the lower btu's per gallon, if memory serves it's in the neigborhood of 98,000 btu per gallon vs. 114,000 btu per gallon on gasoline. You have to burn a little bit more of it to produce the same power so mileage can be down from gas, but again good tuning can minimize that. The lower btu's hurt the mileage, not the power. I will admit this GMC is the first electronic direct port liquid propane injection engine I've had. Everything else has had a carburetor. I understand that the system on this truck uses the oem computer programming (gas), but these computers can certainly be reprogrammed easily. I am doubting there are any mechanical differences between the 3500 and 6500 8.1's in stock gas form, probably just the programming and/or injectors. All of that I can work with.

The truck could be switched easily back to gasoline, all it requires is the fuel rails, injectors and fuel tank and pump, but I like the propane, and I still have friends in the business and can buy fuel at wholesale. Last fall when we brought the truck home propane was $2.79 at Flying J when gas was $2.89, but I bought it wholesale for $1.89 per gallon. So even with a lower mileage I will be way ahead in the $$ per mile. With 160 gallons on board I can do most of my round trips without refueling on the road.

So I guess we won't know until I actually hook a loaded trailer to it and run it up a grade. Seems to run as well as the other truck now, but you can't tell a lot empty.

Thanks for the advice, I am actually impressed that you have some knowledge of propane, most people only know it can cook your burger.

Thanks! Dave

03-18-2011, 06:07 PM	#6
hot rod Senior Member Join Date: Jan 2011 Posts: 527	Eskimo- I'll have to check into the rating on the 6500. I know my 8.1 in my 2001 3500 was the first year for that motor in the duallies, and is not rated as high as the newer 8.1's, I think 290hp off the top of my head. The power level of the propane vs. gas does not bother me, propane was our family business and literally the first thing I ever drove was a Wheel Horse with a bbq tank on the back, and have run everything you can think of on propane, from cars to mdt's to race cars. It's 108 octane and tuned properly can outperform gasoline. The problem is nobody knows how to tune properly. You are correct on the lower btu's per gallon, if memory serves it's in the neigborhood of 98,000 btu per gallon vs. 114,000 btu per gallon on gasoline. You have to burn a little bit more of it to produce the same power so mileage can be down from gas, but again good tuning can minimize that. The lower btu's hurt the mileage, not the power. I will admit this GMC is the first electronic direct port liquid propane injection engine I've had. Everything else has had a carburetor. I understand that the system on this truck uses the oem computer programming (gas), but these computers can certainly be reprogrammed easily. I am doubting there are any mechanical differences between the 3500 and 6500 8.1's in stock gas form, probably just the programming and/or injectors. All of that I can work with. The truck could be switched easily back to gasoline, all it requires is the fuel rails, injectors and fuel tank and pump, but I like the propane, and I still have friends in the business and can buy fuel at wholesale. Last fall when we brought the truck home propane was $2.79 at Flying J when gas was $2.89, but I bought it wholesale for $1.89 per gallon. So even with a lower mileage I will be way ahead in the $$ per mile. With 160 gallons on board I can do most of my round trips without refueling on the road. So I guess we won't know until I actually hook a loaded trailer to it and run it up a grade. Seems to run as well as the other truck now, but you can't tell a lot empty. Thanks for the advice, I am actually impressed that you have some knowledge of propane, most people only know it can cook your burger. Thanks! Dave