Which Diesel Should I Get for a SVO (WVO, VegOil) Conversion?

November 6, 2007

First of all, ANY diesel will run biodiesel. You DON’T need to convert a vehicle for biodiesel. Well, maybe replace a few rubber hoses and seals, but not immediately on putting biodiesel in your tank. Biodiesel is NOT Straight Vegetable Oil.

You can convert any diesel to run on heated, filtered Straight Vegetable Oil (SVO, WVO, VegOil). But, some vehicles are cheap and easy to convert and some are tricky and expensive to convert.

It’s all in how robust the injection pump is.

Common, easier to convert Diesel Cars
1968-1985 Mercedes 200D, 220D, 240D, 300D(SD,TD,SDL)
1977-1992 VW Rabbit(Golf, Pickup), Jetta, Dasher(Quantum), Vanagon 1.5l/1.6l/1.6l Turbodiesel*
1996-1999.5 VW Golf, Jetta, Passat, New Beetle 1.9 TDI (3rd gen)
2002-2003 VW Golf, Jetta, Passat, New Beetle 1.9 TDI (4th gen)

Common, easier to convert Diesel Trucks
1983-1994 Ford 6.9/7.3 IDI (especially the 1994 turbodiesel)
1989-1993 Dodge Cummins 5.9 1st gen 12 valve – rotary VE injection pump
1994-1998.5 Dodge Cummins 5.9 2nd gen 12valve – inline p7100 injection pump**

Other Common Diesels to Convert
1994.5-1997 Ford Powerstroke 1st generation – stock filter issues
1999-2003 Ford Powerstroke 2nd generation – fuel routing issues
1999.5-2001 VW TDI diesels – early 4th gen known for haphazard quality

Common, but more involved and less robust systems***
1982-2000 Chevy/GMC 6.2/6.5 – injection pumps prone to failure
1998.5-2002 Dodge Cummins 5.9 24 valve – VP44 injection pump prone to failure

Many of the newer high-pressure and common-rail diesels are also possible to convert, but are beyond the scope of this quick overview.

Of course, there are the less common diesels by Toyota, Nissan, Isuzu, International, Peugeot, etc. which can also be converted.

* We really like the 1985-1992 VW 1.6l turbodiesels with the Bosch rotary VE pump, although the older Mercedes are built like tanks. (note: not every model is available every year listed)
**The 1994-early 1998 Dodge has the highly recommended Bosch inline P7100 injection pump.
***Alaska VegOil Systems does not convert the senstive GMC 6.2/6.5 or the VP44, although we will help with consultations and can point folks to GMC/Dodge specialists.

Please, folks, make sure your vehicle is running well before you sink some money into converting it. There are too many expensive stories about people who buy a beater for SVO.

In the last two blogs we’ve tried to answer some of the repeat questions people ask of us. Next up we’ll continue our journey through the Alaska biofuels scene.

Veg On!

P.S. More info on the Which TRUCK Should I Get for a SVO (WVO,Vegoil) Conversion? page.


12 Responses to “Which Diesel Should I Get for a SVO (WVO, VegOil) Conversion?”

  1. Dan R Says:

    Great post. Thanks!

  2. Jose de la Maza Says:

    Nice conversions, good experience.

    Have you ever converted a Nissan RD28 6cyl in line, 2,8l diesel, naturally aspirated?

    It has a Bosch injection pump, rotative.

    It is a car motor, very soft.

    Thank you.

  3. Norm Says:

    I noticed a 1993-1995 VW Golfs etc are absent. Why is that?
    I’ve converted a 1987 VW Golf 6 years ago and it’s still going strong. My friend is looking at a 1993 VW Golf Turbo at first I assumed it would be very similar to my conversion. Am I wrong?



    • Will Taygan Says:

      1993-1995 VW diesels were not imported to the US, but are excellent candidates – I would expect them to have a 1.9 IDI (not TDI) engine. Ooooh, how I would love a 1.9IDI turbodiesel!

  4. Mike Goodman Says:

    I converted my 1983 300SD about 60K miles ago. Did my 1982 Rabbit Truck last year.

    I use the DieselCraft OC20 process and usually run 55-gals at 145F-180F for 4 hours. Bone dry, sub-micron from all appearances. Runs to the VW injection pump at ~130F and to the injection lines at 140-185. I usually run the MB in the winter as it generates more heat.

    Question: You say the 1985 and up Rabbit had a rotary pump. Mine is in-line, kind of like the MB. Isn’t that just as robust as the 1985+ pump?

    • Will Taygan Says:

      Every old VW diesel I’ve ever seen has a Bosch VE-style rotary pump. 77-03 Rabbit/Golf/Jetta/Passat. Sure, there’s improvements and electronic controls through the years, but the basic plunger design is the same. In ’04 (with model variation) VW went to a new unit-injector (PD) system, and the currently they’ve got an even newer common-rail design.

      • Mike Goodman Says:

        Not to dense, but with the four lines coming off in a row, I would have thought it like the Bosch on my 83 300 SD.

        In any case, is the VW IP pump stout enough to send a heated blend to the VW IP? I do this from 10% (winter) to 50% (summer) in the MB.

        If any, what blend would you recommend? And at what min temp? Eg: 33% = 120F? Would that hurt the IP on a cold morning? Or can the Rabbit pump take it?

        In the MB, I have a closed-loop return with both an Arctic Fox coolant heated line PLUS a VegTherm Std.

        In the VW, I only have the VegTherm but the WVO injectors are 140+ like I said, sometimes almost too hot, but my readout isn’t right. I may shut down the VTHERM before it gets too far into spring.


  5. Mike Goodman Says:

    And as for the newer pumps, are the electronic controls a problem with negative responses to viscosity changes?

  6. Mike Goodman Says:

    1991 5.9 rotary VE vs p7100 IP’s. Which is better?

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