Frequently Asked Questions

The following is a list of questions we are often asked. Should you have a question which is not listed here, please get in touch via our Contact Us page.

Can any diesel engine run on Pure Plant oil?: In theory pretty much any diesel engine can run on pure plant oil but will need to be converted. There are in practice several inherent weaknesses in some engine designs that compromise the reliability of the engine running on pure plant oil. While theoretically they should run fine in practice certain engine types run into problems in the medium term. The reasons for this are complicated and many fold but they are often centred on the type of fuel pump. We do not convert engines where there has been shown to be an inherent weakness that can threaten the reliability of the vehicles running after conversion. We use the knowledge and experience of Elsbett who have been converting engines to run on vegetable oil for over 25 years, No one has more experience when it comes to which engines will run without problem. If we do not offer a conversion for your engine we recommend utilising the used vehicle market and replacing your vehicle with an equivalent which we can convert reliably. We apologise for any inconvenience but we do not want to offer a service that isn’t as reliable as we can possibly make it.
Can I convert an engine myself?: If you are a competent mechanic and own a set of tools the answer is probably yes, although you will need an injector specialist to change the injection nozzles for any one tank conversions, except for VW/Audi TDi/SDi engines which currently require the injectors to be sent to Elsbett for modification (the carriage price is included in the kit price and the service is quick) We do advise having a conversion fitted by a specialist although as stated any mechanically competent person with automotive tools should be able to fit one, please contact us for your nearest Elsbett installer.
Can I mix diesel in with the plant oil?: In a properly converted vehicle you can mix plant oil with diesel at any ratio. We strongly advise against mixing plant oil and diesel in a non converted vehicle as it may induce engine failure.
Can I use used cooking oil?: If you are prepared to risk the longevity of your engine you can use filtered, de watered and acid balanced used cooking oil but we advise extreme caution for anyone that wants to keep their vehicle running reliably for the long term. Vehicles may run seemingly fine on filtered, de watered and acid balanced cooking oil for some time but there are several problems in consistently achieving a quality fuel from used cooking oil. A great deal of research and experimentation has taken place and we are of the opinion that the use of such fuel has to be considered experimental.
Can you convert new generation diesel engines?: We can convert most modern diesel engines with a twin tank system. We are converting the U.K.'s first one tank PumpeDuse Volkswagen/Audi group engine this month. The Elsbett Kit we will be installing has finished all stages of prodcut development and is ready for export, we are proud to be fitting the first UK one tank system in a new generation engine. One tank kits are in the later development stages for a range of modern disel engines, the bulk of the conversion relies on reprogramming the onboard computer (ECU) to handle burning pure plant oil as well as diesel. We will be the first organisation in the UK to offer one tank PD converesions and we hope to be the first group to be offering one tank conversions for other new generation diesel engines. As stated we can convert a wide range of common rail and unit injection engines with a twin tank system and are looking forward to being able to offer one tank solutions later in the year.
Do I have to pay road fuel tax on vegetable oil?: If you use less than 2500 litres of fuel a year then you no longer have to pay road fuel duty. For heavier users there is a tax break, the tax break is set at 20p below road fuel duty and at time of writing that makes the tax 27.1p per litre. For several years it was an easy matter to register to pay the lower duty rate, however things are a little more complicated now. Our best advice is to speak with your local HM Revenue & Customs office if you wish to self register for tax. You will need to complete form EX103. It is fairly hit or miss as to weather you will get the tax break as a small private user. As of April 2008 an additional incentive - the Renewable Transport Fuels Obligation (RTFO) - will come into effect and should lead to a further 10p a liter price reduction. The other option is to organise your fuel with someone offering a tax paid pure plant oil service, we offer this in the south east and will be able to put you in touch with the most local tax paid oil provider to you (at present they are quite thin on the ground). If you are interested in getting oil to the lower duty rate for the purpose of setting up a seed press or placing a large (at least 1000 litres per delivery) regular order for fuel please get in contact with us as we may be able to help.
How much will the fuel cost?: If you are buying tax paid fuel with the duty rebate it works out at around 90p (VAT included) per litre at present. Savings will be most noticeable to heavy fuel users such as the haulage industry. While this price will change with market fluctuations Pure Plant Oil is set to stay a cheaper fuel than diesel for at least the next three years as it is a rolling three year reduction and any change will require three years notice. (all indicators show that the price of petrochemical diesel is set to reach record highs over the coming years while the price of Pure plant oil should rise at a much steadier pace).
I Have heard some Injection pumps have problems even after being converted: Almost all diesel powered cars and vans can be converted to run on vegetable oil, regardless of which type of injection system they utilise. Pre-chamber diesels, direct-injection (TDI), unit-injector (PDI), and common-rail (CDI, HDI, etc) conversions are all available. However, some engines are unsuitable for conversion using Elsbett equipment due to the limitations of their distribution-injection pump, particularly on traditional direct-injection engines. So distribution-injection systems including injection pumps made by CAV, Lucas, Stanadyne, RotoDiesel or Delphi are not suitable for vegetable oil. If you are serious about converting an engine with these types of fuel pumps we can offer a custom tailor made service for you.
Is it cheaper to buy a conversion kit directly from Elsbett?: No we offer the kits at exactly the same price as Elsbett. We offer the additional service for kits brought through us of a limited amount of technical support from our English speaking engineering team, sometimes critical in getting a conversion right. Unfortunately we do not have the resources to talk everybody through their entire conversion but we can help trouble shoot common problems and offer quick over the phone or by email advice for people that have brought their kits through us.
Is it legal?: Yes so long as road fuel duty has been paid on any fuel used.
Ive heard you can just add 5% white spirits to old chip fat and use it as diesel: Modified Waste Vegetable Oil has been repeatedly shown to be of very dubious quality, we recommend extreme caution when using simple "magic" ingredient fuels. We have been notified of several engine failures from the use of such fuel. Ingredients such as white spirits are also untaxable as a road fuel and therefore illegal to use. We only recomend biodiesel that conforms to the EN 14214 or PPO that meets the DIN 51605 standard in properly converted engines. Use of fuels that claim to be adding a special agent to used cooking oil at the very best should only be used in modified engines, and even in these cases such fuel can cause engine failure. The standards for fuel exist to protect the consumer from fuels of dubious quality always check that the fuel you are using reaches these recognised standards.
Where can I buy tax paid vegetable oil?: At present we offer a service in the south east and can organise regular deliveries of large volumes of tax paid vegetable oil (at least 1000 litres per delivery). If you want smaller amounts we can put you in contact with your most local oil provider, but at this early stage in the development in the use of pure plant oil in the UK, providers are few and far between. There are however more and more local farm scale seed presses setting up to meet the growing demand for this fuel. The other option for smaller scale fuel users is to self register and pay the tax yourselves. Pure Plant Oil can be readily brought at supermarkets and cash and carries, for more information on self registering for tax payment see the question above.
Why do you use Elsbett conversion kits?: We have identified Elsbett (as have most people in Europe) as one of the world leaders in engine conversion technologies. They have been converting engines for over 25 years and really are setting the pace and standard for the whole of Europe. Elsbett only offer conversion kits for engines that have been tried and tested with their equipment to a very vigorous standard and we do not have to rely on hear say that the technology may work. We are 100% confident that Elsbett provide the most advanced and tested engine conversion technologies available in the UK. Please see the Elsbett page for more details.
Will converting my engine effect my MOT?: No, so long as the conversion is carried out correctly.
Will I get less miles per gallon or lose any power?: The simple answer is no, in practice however there may be very small fluctuations in both power and fuel consumption but they vary with engine to engine. Some engines will have a very small amount more power and more miles per gallon while others will have less, in all cases though the difference is only a very small one and often only noticeable under heavy scrutiny.
Will i need to carry out any additional service work on my converted vehicle?: With most of the conversions we offer no additional service works need to be carried out but make sure that the company carrying out the service work are aware of the modification and will not tamper with it. On TDI and SDI one tank converted engines a special high performance plant oil based engine lubrication must be used. Oil change intervals are halved for TDI and SDI engines meaning carrying out twice the number of oil changes in a year. The net effect of this is to reduce engine wear and increase the longevity of these engines.
Will it affect my vehicle warranty?: New vehicles are generally covered by a three year warranty and the engine warranty will be void by most companies if you convert to PPO. We would advise you to contact your dealer / manufacturer to clarify their position. It has been known for fleet operators to get the warranty extended to cover biofuels in consultation with their vehicle supplier / leasing agency. Engine warranties are also generally void if you use more than a 5% blend of biodiesel with normal diesel. The only option for someone wishing to use more than a 5% plant based fuel is to take the decision to invalidate the engine warranty. We are pleased to announce the first UK PPO engine warranty available for converted engine cover for vehicles under three years of age 1,2 and 3 year warranties are available for vehicles over three years old 1 and 2 year engine warranties are available. The Elsbett kits we fit have a parts warranty.
Will it effect my Insurance?: It is worth speaking to your insurance company to check they will cover you, there are many insurers that will. Insurers that provide cover at with no addition to the premium include; The National Farmers Union, Norwich Union Direct, Lloyds TSB and Adrian Flux
Will using PPO have any negative long term effects on my engine?: If you use good quality fuel with a good quality conversion then the answer is no. Make sure that the conversion technology, the installation and the fuel are all of a high standard.

Next: Glossary
Previous: 2003 study of using straight palm oil as a fuel