Our Vegetable Oil Car

While I've been in San Francisco, my husband Larry converted our diesel Mercedes to run on waste vegetable oil. I personally haven't driven the car yet, but I was excited to hear that his conversion was successful and how easy it was to do. -- Debra

Recently, I modified our old diesel Mercedes Benz to run on vegetable oil instead of diesel fuel. This fuel is also known as waste vegetable oil (WVO). The miles per gallon burning WVO is approximately the same as burning diesel fuel, about 27 miles per gallon.

Diesel fuel is now around $4.00 a gallon where I live in Florida, way more than I want to pay just to burn. Also, diesel and gasoline are non-renewable petroleum resources, and I shouldn't be contributing to global warming by burning these fossil fuels when I drive my car.

Vegetable oils are carbon neutral when burned as fuel. They don't produce more carbon waste than the vegetable crop would just biodegrading in the field.

Vegetable oils also have the huge advantage over diesel fuel, because I can get vegetable oil for free. That's right...free. I only have to pay for the cost of the filters, which is still way less than the cost of diesel fuel.

I love driving down the road waving at gas stations selling diesel for $4.00 a gallon. I smile to myself and am pleased that I am no longer participating in the inflated cost of petroleum and the war in Iraq by burning fossil fuels in my car.

Vegetable oil burns cleaner than diesel fuel and it also has better lubrication qualities than diesel fuel, so engines should last longer. So, It's cleaner, greener and cheaper.

How I Modified Our Car to Run on Vegetable Oil

About one year ago, I bought an old 1978 Mercedes 300D diesel car. I bought it with the intent to modify it to run on veggie oil. After catching up on all the regular maintenance things like brakes, oil change, etc., I drove the car around to ensure it was in good running order. Everything looked okay.

Then, I did considerable research on the internet about various different kits to modify diesel cars to run on vegetable oil. They ranged in cost from about $1,000 to $2,000. More than I wanted to spend, but still doable. I continued to look and found a vegetable oil kit made especially for 1977-85 Mercedes Benzes for around $250. This is a single tank system for use in warmer climates (usually above 50 degrees). Since I live in Florida, it was perfect. It's almost always warmer than that here.

I ordered the simple Benz kit from www.fattywagons.com. They communicated quickly and clearly and I had the kit in just a few days.

This time, I actually read and followed the directions. The kit consists basically of a pre-filter, electric injection line heater, a supplementary fuel pump, and an electric fuel heater line that heats fuel before the injection pump. Vegetable oil is thicker than diesel fuel, so it needs to be heated or thinned in some other way before it can be used as fuel.

One afternoon, I installed the kit in my Mercedes. It took about 3 1/2 hours. Most of it was pretty simple put-the-fuel-pump-here-and-wire-it-up-here-to-this-fuse kind of stuff. The part that was tricky was installing the electric injection line heaters with the silicon tape between the injection lines without having it all stick to itself. That tape really sticks to itself very easily and needs to be wound around each injection line. Tedious, but doable.

The kit was very well designed. I didn't even have to cut the metal fuel line or drill any holes in the body. It used existing holes and only the rubber fuel line got cut. Very simple.

I tested the injection line heaters and the injection pump preheater line, and they all worked perfectly. They got very hot in just 1-2 minutes. Perfect.

Now, I needed some vegetable oil. I drove to Costco and bought several gallons of pure soybean oil. This new vegetable oil looked pretty clean, but I decided to run it through a denim cloth just to be sure. This pre-filtering took a little while, but better safe than sorry.

Then, I put the vegetable oil in the fuel tank and I was ready to go for a test drive.

I drove about twenty miles north of Clearwater on US 19. I drove that far to be certain it was running on vegetable oil and not just on whatever diesel remained in the filters and lines.

Voila!

After only a few miles I was driving on pure vegetable oil. The engine ran quieter, but otherwise just about the same as on diesel fuel. Big smile, it works. Diesel cars can be modified to run on veggie oil, and I have one!

Finding Veggie Oil for Fuel

Next, I went to several restaurants until I found one that had decent-looking waste vegetable oil that they were willing to give me for free. The first few restaurants I went to had ugly oil that had lots of garbage floating in it. Finally, I found some primo oil at a nice Thai restaurant (that also has great food!).

I pumped the oil into two 5-gallon containers with a hand pump. The pump had a screen on the pickup end to keep out the bits of shrimp and whatever.

Earlier, I had bought a couple yards of denim for $12.00 at a fabric store to use as pre-filters. I then filtered the waste oil through the denim and into two other 5-gallon buckets. Then, I pumped it into my fuel tank.

Now came the real test: could my car run on essentially free fuel...waste vegetable oil?

I drove about 100 miles north of Clearwater. The car ran great on waste vegetable oil. Free fuel! I smiled and waved at a gas station selling petroleum diesel for $4.09 a gallon.

Cleaner, greener and free (almost) fuel seems to be a much better way to drive.

I did need to make one minor repair. I had some trouble with the alternator pulley squealing and eating its belts. The pulley had been damaged by the previous owner putting on the wrong size belt. So, now that pulley tended to squeal and eat its fan belt rather quickly. This was a problem I had before, but now with the added electric drain from the injection line heaters, what before was borderline was no longer adequate.

Since I couldn't just purchase the alternator pulley by itself, I recycled a whole alternator with pulley ($20) from a wrecking yard! It works great now; no problems at all.

Costs

So far my costs have been:

Diesel Mercedes	$835.00
Fattywagons Simple Benz Kit	$250.00
Denim for filtering fuel	$12.00
Alternator	$20.00
Alternator Belt	$7.95
TOTAL	$1,124.95

A small price to pay.

I've driven over 700 miles on waste vegetable oil so far. At 27 mpg with diesel fuel at approximately $4.00 a gallon, I've saved $103 already! This car will pay for itself in about 7700 miles, and then my savings will be profit! I'll make 15 cents for every mile I drive (and more as gas prices go up and up)! I love it!

It does take 1-2 minutes longer first thing in the morning to start the car when it's cold. This is to heat up the injection lines before starting the car. I'm entirely willing to take this time in exchange for driving on cleaner, greener, cheaper fuel.

One more benefit...The car exhaust doesn't stink of diesel fuel any more. Now it smells like fried shrimp...or fried chicken...or french fries...