Jeep Liberty

System images:

In-tank exchanger
Fuel line
System diagram

Frequently asked Questions:

What's the difference between straight vegetable oil (SVO) and biodiesel?

Can I convert any diesel vehicle?

Which vehicles are the best candidates for conversion?

How hard is it to install a kit?

Will burning SVO damage my engine?

Will the Frybrid system work in a cold climate?

How does power and fuel economy compare?

How do emissions compare?

Will this void my warranty?

How long does it take to get a return on my investment?

Is it legal to use straight vegetable oil as fuel?

Where do I get my oil?

How well do I need to filter and dewater my oil?

What kind of vegetable oil can I use?

How is Frybrid different from other systems?

How does the Frybrid system work?

What if you can't find vegetable oil?

Can I modify my existing diesel tank to be used as the vegetable oil tank?

Will stored vegetable oil go bad?

Can I purchase a Frybrid system without a tank?

Can a Frybrid system be used with a gasoline engine?

Will the Frybrid system allow a diesel engine to run on used motor oil, transmission fluid, transformer oil, etc.?

Is there a warranty on the system?


The diesel engine can be fed with vegetable oils and would help considerably in the development of agriculture of the countries which use it.

The use of vegetable oils for engine fuels may seem insignificant today. But such oils may become in course of time as important as petroleum and the coal tar products of the present time.

Rudolf Diesel 1911


Frybrid manufactures the only commercial conversion systems not incorporating the "looped" fuel return design preventing the overheating of diesel fuel.

Our switch-over times from VO back to Diesel are the lowest available averaging 7-10 seconds on Mercedes applications and 3-5 on VW applications!

Frybrid continuously maintains the cutting edge of Diesel/Vegetable oil hybrid vehicle technology!

Frybrid innovations:

Computer controlled system
No more guessing
Temperature sensing system
Will not switch before proper fuel temp is reached
High efficiency final fuel heat exchanger
Speeds switch-over times to 1/4 of other systems
Vegetable oil / Diesel / Biodiesel specific solenoid valves
Industrial quality components
Component in-tank heater
Billet aluminum unit, every in-tank connection is welded and leak proof
Aircraft aluminum heated fuel lines
Highest heat transfer & longest lasting
Multi- plate high efficiency filter heater
Uses readily available filter with full flow design
Fuel selector solenoid valves
Designed specifically for veg oil and bio diesel with high flow rates
Frybrid Still
A free open source design which can dewater and filter waste oil delivering a safe fuel
On board filtration
The first on board filtering and dewatering system in the industry
Non-reactive systems
The first to conduct advanced studies into the reactivity of various metals on vegetable oils

What we do at Frybrid:

Frybrid manufacturers the worlds most sophisticated system for the conversion of diesel vehicles to use vegetable oil as a fuel. Each and every component of our systems is designed to exceed its system requirements and each exceeds the functionality of our competitor's components. The Frybrid system uses 4 individual heat-exchanging components and is controlled by a microprocessor insuring that vegetable oil below the required safe temperature is never injected into the vehicles engine causing damage. Our system is in fact so revolutionary that we have applied for three patents on various components.

Most systems rely on only a small heat exchanger in the oil tank to heat all the fuel in the tank to injection temperature (160F), the Frybrid system, however, utilizes four. The first being a welded high efficiency coiled heat exchanger in the aluminum, baffled tank with the fuel pickup positioned directly in its center. This assures that all fuel being drawn from the tank is liquefied and lessens the strain on the injection pump and or fuel pump. This single heat exchanger is more efficient than those used by any of our competitors. All internal tank connections for both fuel and coolant are TIG welded to insure a leak proof system. The integral fuel reservoir prevents fuel starvation when cornering, stopping or accelerating when low on fuel. None of the metals in contact with the fuel tank are reactive to vegetable oils and the heat exchanger has more than 30 sq ft of surface area.

Next in line is the Frybrid heated fuel line, this line is connected directly to the top of the fuel tank, the line is made from Aircraft aluminum fuel line running inside a ¾" coolant hose. We have found this line to have better heat transfer than any other line configuration and since our introduction, it has become the most copied fuel line design in the industry.

Next is our Frybrid heated fuel filter, which incorporates a 14-plate flow through heat exchanger through which all fuel must flow before being filtered. This unit heats the fuel efficiently insuring that the filter will not slow the flow of fuel even in cold climates and utilizes a readily available diesel filter element with an integral drain. Other systems wrap the filter in copper water supply line which transfers little heat or use electric heaters which rob the engine of horsepower and strain the electrical system.

Lastly we employ a final fuel heat exchanger which on its own is capable of getting all fuel used by the engine to injection temperature as soon as the engines coolant is at 180F. Again Frybrid was the first to employ this technology which is now accepted as a standard in the industry.

The Frybrid GEN-3 microprocessor is the world's first solid-state vegetable oil fuel system controller and raises the bar in this field. The Frybrid GEN-3 monitors engine coolant temperature and seamlessly switches the engines fuel supply from diesel or Bio-diesel to vegetable oil only when the vegetable oil is at the proper temperature preventing the injection of cold vegetable oil which results in engine damage. It also warns the operator if the vehicle is shut down on vegetable oil, provides system status indicators and automates the purge cycle allowing for faster engine shutdown. Again, others have followed the path Frybrid pioneered but to date no one has developed an equivalent control system. The Frybrid Gen-3 is completely self contained, requires no external components, is environmentally sealed, and has the highest longevity and isolation characteristics in the electronics industry. Nothing else even comes close!

Here at Frybrid our goal is to produce only the highest quality conversion systems, systems that incorporate materials from the aviation, automotive and electronics industries and are constructed to the highest specifications. Our systems are not the least expensive; they are however, the best. We do not use floor-heating tubing for fuel line or transmission coolers dangling in plastic outboard fuel tanks. We do not require that you heat all the fuel in the tank before you switch fuels, or worse yet, manufacture a system which is not capable of heating the fuel sufficiently. What we do is manufacture a system which works, and works very well. A system, which prevents the engine damage associated with other systems, a system we trust enough to have our families use everyday. We remain vigilant in our field and insure through constant R&D that Frybrid is always simply the best system available.