Friday, January 6, 2012

Travel Update: fuel use

We made it safely to my dad’s place in Florida.

In basic numbers that was 1650 miles in 56 hours.

Of course, any trip is more than basic numbers.

This one started with a compromised. The original plan was to leave Tuesday morning, right after my wife’s doctor’s 9:30 appointment. I really pushed for this departure time. It was the soonest we could leave the frozen north, and I wanted to not waste time. Maybe I have a fear of delay. Delays in life have a tendency to stretch on and on until nothing gets done.

My wife had the perfectly reasonable request that things at home get taken care of before we go. She wanted to leave the next day. Finally, we compromised. After her appointment we went home. Together we worked to get the last minute stuff attended to. We left at 2 p. m, only a few hours after my original target time.

We left in bitterly cold conditions. Temperatures were near zero combined with high winds. The truck was laden with 200 gallons of waste vegetable oil for fuel. WVO at those temperatures really isn’t liquid. Most of my oil was high quality canola. It’s solidifies at lower temperatures than most vegetable oils, but it was too cold for even canola. The last batch of oil had been loaded from a warm basement the day before and it was just barely liquid. The rest of the oil had been loaded earlier and was mostly solid.

WVO use was a big part of my travel plans. The truck, a Ford F250 with a 7.3 turbo diesel, uses a lot of fuel, especially pulling a sailboat. I could not afford to burn diesel all the way down.

My truck is a simple straight vegetable oil conversion -primitive even. The truck has two fuel tanks, one for diesel and one for WVO. It’s started on diesel. Engine coolant runs though a copper coil in the WVO tank that heats it up. WVO has to be hot to lower its viscosity, otherwise the engine won’t run properly, if at all. Once the oil is hot, the truck is switched from the diesel tank to the WVO tank.

The super cold temperature made it difficult for the WVO tank to get warm enough. Heat loss though the uninsulated tank really increased transfer times. I had to burn a lot more diesel to warm the supper cold veggie. Worse, at highway speed, the oil has be super hot to flow fast enough, but the wind chill on fuel tank made that hard to do.

Then there was the problem of getting more oil into the tank. The oil jugs stored in the center of the truck bed were a bit more liquid. I used them first. Even so, it was a lot like pouring molasses into the tank. Fueling up took a lot of time.

Normally, adding 5 - 10 gallons of veggie into the tank doesn’t drop the temperature enough to matter. Cold as my fuel was, it clogged up the system. I had to switch to diesel for a bit to bring the temperature back up.

It became harder and harder to find oil liquid enough to pour into the tank. I had to use the top few inches off of many different jugs as the fuel freeze from the bottom up. It took a lot of jugs to get enough fuel to keep going. As you can imagine, that took time and a lot of fuel handling.

Once we got down to North Carolina, temperatures were up to 35 degrees. That was warm enough that the oil started to flow again. The further south we went the warmer it got. Eventually, fill ups were quick and easy.

The final fuel bill? About 30 gallons of diesel, plus many gallons of free WVO. Take 1650 miles and divide it by 30 gallons. We got 55 miles per gallon for every paid for gallon of diesel. Now on a good day, with a light load, the truck only gets 15 - 18 mpg in real fuel use. With a heavy load in the mountains, I bet we got closer to 10 mpg -maybe less. Of course, as we used veggie fuel, lightening the load, and got out of the mountains, mpg went up.

It was a hassle to use veggie fuel, but it saved me hundreds of dollars. That’s money I can use to enjoy my time here, so it’s worth it.

More about the rest of trip down later.

We are here safe and sound. (and tired)



  1. Glad you made it. Sounds like an insulating blanket would be a good addition to your fuel tank!

  2. Craig: Yep, but it usually isn't a problem. Just the combination of extreme cold plus pushing the truck to highway speeds under load.

  3. You should know better.
    Sailors cannot travel on a schedule.
    Only stinkpot folks travel on schedules, and pay the price.
    True experienced sailor would have just waited for a better weather window....
    I think you just drug all that damn cold down with ya ! Thank god it's warming back up ! Supposed to be 75 here in Melbourne today.
    Welcome back to Floriduh

  4. Glad the trip went OK and welcome back to my state!
    I probably missed your postings about your veggie conversion but I am very interested in how you put your system together with some photo's to help understand what you've done would be great.

    Have fun,

  5. Glad you made it, even if the cold gave you some problems and cost you some extra fuel dollars. May you and your wife have a wonderful vacation. We may be heading over that way soon to visit some friends.

  6. Spud: You are right, but I really wanted to get out of Dodge.

    Yukon: Thanks, good to be back.

    Dizzy: you have a safe trip too. Going to use that big new motor home?