VW Polo running on vegetable oil - no modification needed
For the last 600 miles, my Volkswagen Polo 1.4tdi has been running on a mixture of diesel and vegetable oil.
It's an experiment I've been wanting to run for 2 years but I'd been put off by the antiquated Inland Revenue taxation regime on fuel. That was scrapped recently so you can now put vegetable oil in your car without paying fuel duty. (Check that your car can run on biodiesel before trying this!).
I have done no modification to my 2001-built VW Polo so I was a little apprehensive for fear of damaging the engine. The car is designed to run on diesel, but the handbook states that it can run on up to 50% RME (Rapeseed-Methyl-Esther) mix, so I should be safe. Some diesel engines require modification because vegetable oil is more viscous and puts more strain on the fuel pump. It can also be harder to start the engine in winter.
To minimise the risk, I used a 1:4 mixture in my first tank. My mix is:
- 80% diesel
- 20% vegetable oil
The fuel tank capacity is 10 gallons (45 litres). So I put 9 litres of vegetable oil into the car, then filled it up with diesel.
The price of diesel recently rose above £1.00 per litre. Vegetable oil costs about 55p per litre in the supermarket. So, by using a 25% mix, I saved about £4.05 on a tank of fuel. On my next tank, I will use a 50% biodiesel mix, and will save over £10 per tank.
There was no noticeable change in the average MPG (miles per gallon) - I recorded 68mpg which is what I achieve with standard diesel.
Biodiesel is, arguably, better for the environment than diesel. It comes from a renewable source and the CO2 emissions are equal to the sequestrated amount when the vegetable grows, so it is carbon neutral. However, some people believe that it is contributing to the destruction of rainforest as Malaysia, Indonesia and other developing countries cut down their rainforests to plant palm oil, which can also be used as a biofuel.
Seeing as I am burning sunflower or rape seed oil, I don't think I am having a direct effect on rainforests. But if I wanted to run the ultimate biodiesel car, I would copy my mate Adam and collect used vegetable oil from the local fish and chip shop, run it through a filter then stick it in my car. It's free and it's an otherwise waste product. Everyone's a winner!
If you want to investigate biodiesel, there are lots of useful websites. I recommend this one to start with.
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Paul Maunders said,
November 2, 2007 @ 12:54 pm
Jake that’s brilliant.!
I’ve always wanted to try out homebrew veggy oil fuel, but never had a diesel car to test it out on. I also wasn’t aware that the law had changed, so they must have snuck (or is it sneaked?) that piece of news out the back door!
2500 litres a year tax free should be plenty for most people.
Paul Maunders | Web log » Blog Archive » 2500 litres of biofuel a year tax free said,
November 2, 2007 @ 1:37 pm
[...] My friend Jake is currently trying out a blend of 20% vegetable oil, 80% diesel in his unmodified VW Polo and has so far driven 600 miles with no side effects! [...]
jakebrumby said,
November 2, 2007 @ 2:17 pm
Not only will it save me about £200 per year in fuel costs, I just re-taxed my Polo for 12 months for the paltry sum of £35. Fully comp insurance costs me £220 per year with 5 years NCB.
What would be very cool is a tool to measure the total running cost of motoring for different types of vehicle. It could include fuel cost, tax, insurance and possibly even running costs (if accurate data already exists). I think the Polo would come out pretty well!
jakebrumby said,
November 16, 2007 @ 12:50 pm
This BBC reports on why biofuels should come from a sustainable source:
http://news.bbc.co.uk/1/hi/sci/tech/7096819.stm
Matt said,
November 18, 2007 @ 12:37 am
N.B.: Biodiesel does NOT equal vegetable oil. Wikipedia.
Ward said,
November 18, 2007 @ 1:16 pm
Look guys, I know it feels great to not contribute to carbon emissions, but I must agree with Fidel Castro. The idea of using food products for fuel is madness. The problem is not the fuel, it’s the internal combustion engine. We are still using a mode of propulsion that is simple outdated. We have alternatives but not the political will to develop them. Think of the person who could use that cooking oil. And while it may cost less than diesel, don’t forget the carbon emissions that were produced to grow the sunflower seeds, process that oil and to create the plastic bottle and transport it all to the supermarket and then to your home.
I am an Australian who lives in Brazil and there is now a madness to cut down trees and plant more sugar cane for biofuels……consequence.. the price of sugar has doubled.THIS IS MADNESS
Marc said,
November 18, 2007 @ 4:15 pm
You need to be careful while doing this in the United States of America. Here in the states, road tax is applied through gas prices. If you go completely biofuel, such as oil from your local fish and chip shop (or fastfood joint in the states), you need to pay your road taxes. If you are caught not paying your taxes, it is a large fine and jail time.
Good idea though! Just pay your taxes!
Stu said,
November 19, 2007 @ 3:29 pm
“That was scrapped recently so you can now put vegetable oil in your car without paying fuel duty.”
Um, when did this happen? Could we have a citation please?
chris said,
November 19, 2007 @ 8:04 pm
i had a VW jetta in the states, i ran it on used cooking fryer grease. it smelled like french fries when you started it up
Steve Noolan said,
November 19, 2007 @ 11:46 pm
The problem with running on straight vegetable oil (SVO) is the polymers that form when the Glycerin molecule is burned.
These form a kind of plastic that causes sticking of the piston rings, and coking of the combustion chamber, valves and injectors.
This is a long term build up and will take more than 600 km to show up. Often it will take 15-20,000 km. It would be prudent to dismantle the engine after 10.000 km and assess the effects.
Heating the oil (modifying the engine) or removing the Glycerin molecule (ie turning it into Biodiesel) is the only way to overcome the problem
Luke said,
November 20, 2007 @ 6:32 pm
Older diesel like 80’s Mercedes-Benz can run on 100% regular supermarket vegetable oil, and if you have some patience and a basement (or other suitable place) you can even tank for _free_. Collect used deep-frying oil from fast-foods, restaurants etc, filter it with a cloth, and run your old Benz without any modification.
Tested and working, but it may be “not exactly 100% legal ” in some countries, so check what the law of your country of residence has to say first.
jakebrumby said,
November 20, 2007 @ 10:22 pm
As requested by Stu, the rules for taxation of biofuels were changed on 30 June 2007. HMRC removed all taxation and the requirement to fill in a tax return each month, providing you do not use (produce) more than 2,500 litres of fuel per annum.
http://www.hmrc.gov.uk/briefs/excise-duty/brief4307.htm
2,500 litres of vegetable oil will fuel your car for more than 22,000 miles at 40mpg. If you mix it with diesel at 50% and your car does 68mpg like mine, your annual allowance is enough for 74,889 miles.
George said,
November 22, 2007 @ 1:02 pm
@Ward: I agree with you that current attitudes to travel (i.e. cars) are not sustainable, but I must object to the idea that someone can cook with vegetable oil thrown out by chip shops. Firstly, how would you get that oil to people that really needed it (e.g. in Africa) - how much would that cost? Secondly, the oil isn’t fit for human consumption. That’s why they’re throwing it out. The oil slowly oxidises and becomes rancid (that’s why you can smell a bad chippy long before you get there) and also the oil starts to carbonise at the very high temperatures producing some quite nasty carcinogens. Either they chuck this oil away (landfill anyone?) or we can use it for fuel (which should be mandatory).
As the average commute takes 45 minutes in the UK, you could very comfortably cycle 7.5 miles in that time (based at on 10mph average). IMHO any commute less than 10 miles should be bike. Before people moan about hills in their area, I recently cycled End-to-End with my 60 year old father and at no point did our average speed drop below 12mph - that includes going through the winding hills of Cornwall, the peak district and the Scottish highlands. I doubt many of you have to face Rannoch Moor on your daily commute. No car = one massive saving. What would be nice to see is that vegetable oil going to power public transport for those who can’t cycle.
Uriah said,
November 24, 2007 @ 6:55 pm
rape seed actually produces more greenhouse gases than oil-based fuel. http://www.timesonline.co.uk/tol/news/uk/science/article2507851.ece
not to mention is gonna cost you serious money to replace your fuel pump when that veggie oil builds up.
But hey, as long as you feel better about yourself by using vegetable oil, go for it.
Pritesh Hirani said,
January 14, 2008 @ 5:39 pm
Hi Jake,
Just have a few questions I wanted to ask regarding using vegetable oil in this car with no mods. How many miles have you now covered? Have you experienced any mechanical problems and lastly have you increased the mix to above 50:50?
thanks
Pritesh
jakebrumby said,
January 14, 2008 @ 7:00 pm
Hi Pritesh,
I discovered during winter that the air temperature is a critical factor. When the outside temperature in the UK fell to between 3 to 10 degrees Celsius, the fuel pump started making a quiet squeal (using a 50:50 mix). This was because the fuel was more viscous and it was harder to pump the fuel through the thin tubes. I moved back to a mixture of 80% diesel and 20% vegetable oil and the car was fine. I had successfully been using 50:50 mix without problems in warmer weather.
This suggests that during summer, I could probably run it on 75% vegetable oil and possibly even 100%.
My car has done 106,000 miles of which the last 3,000 have been using biodiesel, so my experiment is by no means conclusive. So far there have been no mechanical problems and I am comforted by the fact that VW state that you can run the car on up to 50% RME.
If I were you, I would start on a mix of 25%, see how the car runs and then increase it gradually.
Good luck,
Jake
andy mole said,
April 18, 2008 @ 3:41 pm
I have a rover diesel and have run it on a 60 diesel 40 veg with no problems, but the supermarkets have decided to cash in, so veg oil is now nearly the same price as diesel, so the government gives and the supermarket take.
D.Thomas said,
April 29, 2008 @ 1:19 pm
I run a 1994 1.4 diesel Ford Escort Van for short runs, (not business). I tried veg.oil in normal diesel for years.
For a short period it ran on pure veg.oil, but it was slow to start, and once I had to use an ‘easystart’ spray in the air-intake. It was also sluggish power-wise,(how much the tired engine counts,I can only guess).
Starting on 50% veg.oil with regular diesel seems to be OK, but because it is outside all the time I use pure diesel in winter because of the slow-starting.Veg.oil is available in 3700 kj and 3400 kj (see energy value on label):I’m careful to use only the 3700 stuff.
Because of the old engine, four years ago I fixed a Broquet fuel-catalyst in my fuel line.(It improves engine-performance by improving fuel quality). This may help the use of veg.oil too; I’m no technician but it seems reasonable.
Cheers,
D.Thomas
Gary Matthews said,
June 12, 2008 @ 11:11 pm
I run a Vauxhall Cavalier 1.7 Turbo Diesel. I wanted a diesel for some time, just so I could try out vegetable oil. I was very lucky that someone wanted to get rid of this car & I got it for free. So I was in a great position to experiment as I still had my petrol Ford Mondeo to fall back on.
I initally put one litre of Rapseed oil in. Over a period of 8 months I have gone up as high as 95% oil, although both times, the air temperature was cold, the last time was when in snowed in Brighton, I think from memory that was in April.
Each time I went this high, the car broke down after a couple of miles. Sensibly, I always carry 5 litres of diesel in the car, and both times it broke down I poured the diesel in the tank, left it 5 minutes & the engine re-started.
I am currently using 90% oil with no problems. My latest venture is to now try the car with filtered only waste vegetable oil which I have sourced from my local kebab shop for free. I have filtered the oil down to 5 microns as I understand the fuel filter on the car only filters it to 10 microns. I have not used caustic soda & methanol.
I hope this information is of assistance to anyone thinking of giving it a go.
Wish me luck, as I have now got rid of the Mondeo (Too expensive).
Gary
Paul Bartlett said,
August 17, 2008 @ 5:23 pm
Actually, I am an owner of a kebab / take-away shop and waste around 20l a week of veg oil for cooking. What’s the best procedure to run my Polo TDI Sport (03 model with the 75 BHP engine) on used chip fryer oil?
Jake said,
August 19, 2008 @ 9:15 am
Paul,
Check your Polo manual and it should say that it can run on 50% RME (Rapeseed-Methyl-Esther). It’s a different engine to mine, but I suspect you’ll be able to run it on biodiesel.
Filtering oil takes a bit of time to set-up but it is worth it for the free motoring! There are lots of options for filtering the used oil (known as WVO - Waste Vegetable Oil). Have a look here:
http://www.biodieselcommunity.org/filteringoil/
A friend of mine used two oil drums - one of top of the other - and filtered the oil through old socks and rags. Very enterprising and low cost.