Vegtherm Mega SVO and Biodiesel Heater, 32A max. amperage draw, (384W max @ 12VDC) use with all applications such as pickup trucks, etc. that get less than 25 mpg US gallon. , includes auto-reset circuit breaker, Bosch relay, connectors, wiring, bumper sticker, and instructions. Comes complete with hose fittings to accept 3/8" fuel line. Overall length: approx. 9 inches

Our Vegtherm has been a very popular item for heating vegetable oil and biodiesel. Thousands sold. Extremely well made and reliable.

The Vegtherm gets very hot, very quickly. Fully hot in about 40 seconds at zero flow rate. Therefore, it can be installed to switch to SVO at the same time SVO is selected, in fact, the same "trigger" that switches a valve to SVO can turn on the Vegtherm. it allows for switching over to SVO fuel from diesel or biodiesel more quickly than if using engine coolant alone as the heat source for SVO (if using a two-tank system). We switch over when coolant is around 100-140F. We have been using this method for 6 years, many of our customers have adopted it as well, we do not get reports of problems with this approach. We also offer the SVSW60C Early Switchover preventer which can be used to prevent a valve from switching to SVO until engine coolant is 60C/140F. This can be used where gauges do not show engine temperature, and owners wish to eliminate guesswork.


The Vegtherm consistently delivers substanitally higher SVO temperatures and is often added to coolant-only SVO systems to improve their overall performance. Sized to heat room-temperature oil to approx. 70-80C /158-176F at typical fuel flow rates of the engines and miles per gallon mentioned, at cruising speed with a looped return. Uses solid state, advanced heating technology with inherent self-limiting function.

Alternator and belt must be in good condition. If the alternator, belt and battery are in good shape, and the unit is used as directed, the Vegtherm can run all the time, and not cause a problem for an alternator at all. We recommend that the rated output be at least double that of the Vegtherm, so for this model, at least a 40A alternator. We and many customers run with daytime running lights (headlights on all the time), long nights, long winters in Canada, with heaters and rear defrosters, etc. operating, and do not have problems. The new VTSW80C thermoswitch and tee/fitting can be added if desired, to prevent the Vegtherm from heating oil past 80C, but it is not needed in many cases.

The more fuel efficient cars, idling in summertime can experience SVO temperatures in excess of 212F - some people are concerned about that, even though we have not had any reports of problems created by this, and even though studies such as the ACREVO study (Google it) suggest that for best combustion, comparable to diesel fuel, temperatrues be in this range all the time (and especially at low engine loads).

In any case, to allay any fears some users might have about higher SVO temperatures, we have introduced that optional VTSW80C switch as an option that is simple to add, wire, and will automatically further limit the high temperture cutoff point of the Vegtherm from that which is achieved with the high temperature inherent cutoff point of the heating elements themselves.

The Installation Manual does not ship with the product. Rather, we send it to you in PDF format when we send you a shipping confirmation. We also tell you where to download Adobe Acrobat, in either Windows or Mac versions, in case you don't have it, so that you can open the PDF attachment.