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New personal record: 64.75 mpg on B100 using lp

4K views 19 replies 7 participants last post by  racinmike77 
#1 ·
I took a trip to Kansas City and back a few weeks ago. Filled up the tank with B100 to the brim. Drove the round trip, which was 1525 miles, then towed my dovetail trailer another 30 miles here. Finally got around to filling up the tank today. Total miles, 1554, total gallons 24. I think I got around 16 mpg on lp. That comes to 4 gal of lp to 1 gal of diesel. Now I need to get a bigger natural gas tank so that I can save more, since lp has gone up so much since I started doing this several years ago. To the best I can calculate, the lp saved me 4.2¢/mi, for a total trip savings of $65. Not alot, but I didn't have to make any fuel stops either.
 
#4 ·
sorry its kinda off topic, how does that 4bt hold up in your sub? Just curious as I might eventually do a 4bt swap into my cucv m1008 with a 4l80e attached to it. That is great mileage even though you are still buying the lp. What are your thoughts on the hho onboard generators(as a fuel supplement)? any experience? There is a discussion over on ck5 about that very thing at the moment.

Remington
 
#5 ·
I did the Kansas City trip with my Duramax. The 'burb is working fine, but I can't use nearly as much lp because the engine is working much harder and with no intercooler it pings easily with too much gas. I haven't got alot of all highway numbers yet on the burb, but with the lp it has plenty of power. I took a trip to Washington DC a few months ago and got 27.7 mpg on #2 and 55 on lp. It is mountainous and I ran no less than 70 mph up all of them. Subtracting the contribution of the lp would have put it at 21 mpg if all #2, which isn't bad for a 6K lb car doing that speed in the mountains.

Regarding the hydrogen generator, here are a few threads to check out.

http://www.dieselplace.com/forum/showthread.php?t=171478

http://www.dieselplace.com/forum/showthread.php?t=192747
 
#6 ·
Marc,

I have been reading quite a few threads on the archive relating to your kit and am very interested. I drive a stock '93 Chev. w/ 6.5t. I do have a question about the mileage that you have been able to get with the LP. Over the last 2-3 years, you have been able to get better and better range on your diesel tank. Have you been able to achieve this by fine tuning the mount of lp flowing? Do you tweak the lp flow as you drive to accomodate the conditions (i.e. cruising, climbing, passing, pulling, etc)? I'm not sure how my tranny would handle the extra power. I've thought about getting the B&M shift improver module. Thanks for your input.


Andrew
 
#7 ·
Andrew,
I used lp on my 6.5 for 10K miles before it cracked a brand new head due to a defective casting and I ruined the engine. My daughter took it on a trip and she went 1140 miles w/o a fillup. It took 38.5 gal of #2 and 45 gal of lp, which comes to 29.6 mpg for #2 and 25.3 mpg for lp. I don't think you will hurt the 4L80, it can handle the extra zip. It really helps the 6.5 on the hills.

I wasn't able to run the 6.5 enough to really see what the optimum diesel mileage could be. But you can see that it isn't hard to do more than 50%. Another thing about her trip: I didn't realize it until after she returned that the waste gate wasn't working on the turbo, so it would have had little to no boost. It still climbed the hills better than it did with the turbo and no gas.

I have improved it over the last few years regarding optimizing the lp to #2 ratio. The only reason to run alot of lp is if you can buy it cheap enough. This last year I have been working alot more on cng since it is so much cheaper than lp now. I plan to put a 6 gal bottle of cng in my 'burb and see how the 4BT likes it. I should be able to greatly improve the #2 mileage since cng is much more resistant to detonation than lp.
 
#8 ·
Marc,

From what I have read about your kits, I like the concept that you are using. The kits are well thought out and simple. Now having said that, is it possible to get even simpler if one is not trying for the economy volume of propane, but would like a little extra OOOOMPH up the hills.

Here's the basics of my thoughts(you may have heard all this before and if you point me to a previous response, that's fine). A system similar to yours but running off a vapor tank, hopefully eliminating the need for the heated vaporizer. Since less propane is being used, a smaller(hopefully) cheaper regulator. The one drawback to this idea is that enough propane to provide some boost may freeze the tank up.

Well, this may all be a pipe dream, to construct a cheaper system by using smaller vapor tanks and a smaller regulator, to achieve a smaller purpose. Any thoughts you might have would be great.

The reason I am thinking this way is the MONEY thing. The price of propane here is such that I can't run propane just to save money, it's too expensive here. So I figure if I can't recoup the kit cost in savings, try to do a cheaper kit to get a little boost. Thanks for your input. Andrew
 
#9 ·
You can get a simple bbq propane tank. Those are not so highly pressurized like automotive tanks.

You can use a simple regulator with those tanks. The whole system should be under $100, including the solenoids and hoses. I advise you to go for 2 solenoids, one right after the tank and one in the engine bay.


One question for those experienced with propane. Is anyone using it on an idi engine?
 
#10 ·
You can get a simple bbq propane tank. Those are not so highly pressurized like automotive tanks.

You can use a simple regulator with those tanks. The whole system should be under $100, including the solenoids and hoses. I advise you to go for 2 solenoids, one right after the tank and one in the engine bay.


One question for those experienced with propane. Is anyone using it on an idi engine?
A BBQ tank is under the same pressure as an automotive tank. If it has liquid propane in it, it will have a certain amount of pressure based on its temperature. A BBQ tank is not DOT approved. If you get caught in a motor vehicle with it hooked up to the vehicle, you can get fined, especially in an accident.

You can make a non-modulated system just to dump a fixed amount of gas with a toggle switch for cheap.

LP works on IDI engines, but not as effectively as DI. The 6.5 is IDI.
 
#11 ·
Thanks for the feedback.

If I were to install a propane system, it would only be a modulated one. I guess I wondered about using a vapor tank because I already have several. forklift tanks don't seem to be extremely expensive so I should not try to cut that corner. I would rather keep truck the way it before I'd install anything that is "iffy".

I must admit, Marc, I've studied your system carefully and wondered if I could build a similiar system cheaper on my own, but then I know that I receive no benefit from your experience.

I guess for now I'll keep reading and learning.
 
#12 ·
Most forklift tanks have liquid and vapor outlets. They are ASME certified, so it is no problem to use them on motor vehicles.
 
#14 ·
#19 ·
marc how much money can I save on fuel costs by running propane or cng? I get 17mpg on #2 and am paying $4.19. I am seriously considering propane or concocting up some bio.
That all depends on the price of lp and cng. Natural gas is going to be way cheaper, but has a higher upfront cost for the system. Unless you have access to a refueling station, you will need to compress it yourself. What do you heat your home with? If you use lp, you can put a pump on your tank and fill your truck, and you can buy it in bulk and maybe do better. I'm sure that the natural gas will be much less than lp, even in bulk. Let me know what you heat with and how much you pay for it and I'll figure out what it will save you. I just put a cng system on a semi and am waiting for mileage data. I'll post the results as soon as I figure them. The owner is already thinking of getting CAT to detune the engine from 550 hp back to 400 because the cng has given it so much more power.
 
#18 ·
"You can make a non-modulated system just to dump a fixed amount of gas with a toggle switch for cheap".
That is what I did.
 
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