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Many diesel vehicles can be run on ‘biodiesel’.  This has been popular with environmentalists for a number of years as bio fuels are (a) carbon neutral and (b) can have significantly reduced emissions, not to mention a bio degradable non-toxic product rather than a petro-chemical one.  However, the main reason for their cult popularity is that it is possible to make biofuel such as biodiesel from waste, e.g. the used oil from chip shops.  This can result in cheap fuel!  Until recently biodiesel was subject to tax of 27.1p/litre which has now been scrapped and, provided that you use less than 2,500 litres of fuel a year for your own personal use, you no longer have to pay tax to use it legally (http://www.hmrc.gov.uk/briefs/excise-duty/brief4307.htm).

Note: In Customs jargon ‘producers’ can mean users, e.g. if you buy oil from the supermarket and fill your car tank with it you ‘produce’ fuel in their eyes. 

This means that it’s now also economically viable to use a range of fuels, from biodiesel to SVO and WVO.  SVO is straight vegetable oil, i.e. liquid vegetable oil you buy from the supermarket.  It’s very similar to diesel in burning/combustion properties, other than it’s thicker.  WVO (waste vegetable oil) is SVO that has been used, i.e. the tubs of oil that your local fish and chip shop has to get collected and disposed of every week when they change the oil in their fryers. 

Some vehicles, notably old Mercedes and slow running engines with ‘in line’ injector pumps, have run successfully without any modification on SVO instead of diesel.  Others like the Bosch pump Peugeot 1.9 diesel XUD engine can run on an 80% SVO/20% diesel mix or similar.  However, many people running on oil are doing so at less than optimum levels.  If an engine is designed for diesel and trying to run on thick oil various things can happen ranging from nothing as it runs fine, to running acceptably but giving less mpg/performance, to engine damage.

The potential for savings is large, especially if WVO is available at little or no cost if you know someone in the catering business.  SVO is around 70p a litre and good quality WVO just requires settling and filtering down to 1 or 5 micron to be used in the same manner.  This is then a good fiscal argument for converting a car to properly run on oil.

A Twin Tank system is the best way to do this.  The principle is that oil, when heated to 70^o C or higher, reduces is viscosity (thickness) and is then as thin as diesel.  This effect can be seen in a frying pan where hot oil or fat is as thin as water but if left until the next morning it has thickened on the pan!  So with a few minor adjustments such as altering the injection timing slightly (done via computer on VW TDi systems) if we have a system that starts and stops on diesel, we don’t have to worry about any thick oil doing damage or even running badly when the engine is cold.  A Twin Tank system has fuel heaters that heat up the oil fuel and will, in an automated system, only allow switch over to the oil fuel from the oil tank when the engine and fuel is hot.  At this point the engine is perfectly happy to run on the fuel.  Warm up time is quick.  You can be running on oil as quick as your car gets warm upon starting, typically 3 or 4 miles.  The rest of the journey uses no diesel!  At the end of the journey an automated system ‘purges’ the fuel system by flushing it with diesel and then switches back to standard diesel mode.  This ensures that no oil is in the system for the next start up.  If you forget to switch over, a buzzer alarm sounds to remind you to, avoiding the possibility of wondering if you dare start your car next time in case of damage!

Some basic kits come with manual control.  This is something we are not happy to fit as one day someone, somewhere, will accidentally change over at the wrong time or forget to change back.  The kits we recommend are the fully automated sort.  Depending on the vehicle you can either have oil in your vehicle tank and have a 2^nd small tank fitted in the boot for diesel, or have a larger in boot tank for oil and keep the original tank for diesel.

We are currently working with Smartveg (http://www.smartveg.com/) who have the most advanced control unit that monitors and displays information.  We have also fitted kits from Dieselveg (http://www.dieselveg.com/) and have been asked to produce our own kit for people on a budget who still want the automated change over but without the complexity or cost of some of the other systems.

While we are working to establish closer links with suppliers please feel free to choose your kit withfree advice from us.   We can then offer fitting from £300 for a typical full Twin Tank kit. 

If you have any questions or would like a chat, please use the contact us option, by clicking here, or below.

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