PowerSwitch

Dave K · Joined: 23 Feb 2012 Posts: 2 Location: Hertfordshire

Hi,

This is the first time on the forum, and I'd like to know how easy it is to run a converted diesel engined car on veggie oil, i'm considering buying an already converted diesel jeep cherokee 2.5l. How easy is it to pay the tax to HMRC when you buy the oil? Who would be the best supplier (e.g chip shop)? Does the change of fuel make the efficiency any better? Are any of the conversion kits better than others? Should I look for a particular one? Is it best to buy the oil in bulk and store it? Does the oil have to be used? Or can you use 'clean' oil to run on? Can you run solely on veg oil or will the system need to be flushed with diesel when you finish your journey?

Sorry about the amount of questions, I'd really appreciate any help with this that I can get.

Thanks in advance

Dave

adam2 · Posted: Fri Feb 24, 2012 4:48 pm Post subject:

Welcome.
To run a car on straight vegetable oil does require some modifications, and to ensure ready starting usually requires shutting down on fossil diesel.

If instead the veg oil is processed into bio-diesel, then many engines can burn it without modification.

You may be able to obtain used oil from fast food shops, but there is far more competition for it than in years gone by.
_________________
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"

Tarrel · Posted: Fri Feb 24, 2012 5:43 pm Post subject:

There are basically three approaches to running a car on veg oil:

1. Convert the veg oil to biodiesel. This basically involves removing the glycerine in the oil and replacing it with methanol. It can be done at home and there are various companies that supply the kits. It is not without risk, and does require an energy input as the oil needs to be heated and stirred. Most diesels should be able to use biodiesel unmodified.

2. Use new vegetable oil, or filtered used oil, and mix it with diesel. The amount of oil you can get away with will vary according to the ambient temperature. Advice I have had from people who have tried it suggests that you can use around 50-60% veg oil in summer, but as low as 25% in winter. You just mix it with the diesel and pour it in the tank. Opinions vary regarding the long-term effect on the engine. It appears to depend on the type of injection system. Common rail diesels, with no injector pump, seem to fare better.

3. Modify the vehicle to use straight vegetable oil. This normally involves introducing a heater into the fuel line and maintaining a small tank for diesel that is used to start the vehicle and run it when cold, before you switch over to the main veg tank. This is probably the way your potential car has been done. In this case, if you are going to use used oil, make sure it is well filtered.

In answer to your other questions:

Re. tax: The rules changed a few years ago. Provided you don't make or use more than a certain amount, and provided it is for personal use, you don't have to declare or pay duty on the use of veg oil or biodiesel. I think the amount is 1200 litres per year, but don't quote me on that.

Re. efficiency: Most experiences I have read, through Land Rover forums, etc, generally refer to a slight reduction in efficiency when using veg oil. People also say they detect a slight improvement in running, though this may be subjective. You definitely get a chip-shop smell out of your exhaust though!

One other thought; if you are going to use new veg oil from the supermarket, don't expect much of a saving. Last week, Morrison's own brand was going for around £1.54 per litre. I'm sure you'd get a reduction if you bought in, say, 10 litre drums in Makro, but don't expect too much.

A lot of fast food outlets and restaurants seem to have cottoned on to the idea of cars running on veg oil, and many now charge for you to take the oil away. Still much cheaper than buying new though.

Hope this helps. There is loads of stuff on the net about this.

Tarrel · Posted: Fri Feb 24, 2012 5:44 pm Post subject:

Sorry Adam2, just noticed that some of my points were covered off in your reply Embarassed

stevecook172001 · Joined: 08 Mar 2008 Posts: 2286 Location: UK

Tarrel · Posted: Mon Feb 27, 2012 4:25 pm Post subject:

I'll be acquiring an old Land Rover that can run on straight vegetable oil for use around our woodland later this year. I'm doing this not as a sustainability measure but more to achieve resilience.

I envisage a scenario in the near future where we transition from the "situation now" to a post-carbon, localised, neighbourhood based economy. That transition will take some time (barring an all-out fast collapse), and I imagine it will be marked by temporary, but increasingly frequent, difficulties with supply of fuel and other commodities. During this time, in order to survive economically while the old system struggles on, one will need to try to conduct business as usual. Having a vehicle that can run on veg oil is one way to achieve this. (In fact an old Land Rover will run on practically anything. I understand the RAF have run them on Jet A1!).

Other resilience measures include (planned and in progress):

- Starting up a local-based business based around a needed product (firewood)
- Reducing base-line expenditure so that a greater portion of spend is discretionary
- Switching to renewable energy heating (solar thermal and wood-fired)
- Living in a location within a short walk of both rail and bus public transport, and shops
- Setting up a kitchen garden (soon, I keep promising myself!)

stevecook172001 · Joined: 08 Mar 2008 Posts: 2286 Location: UK

Tarrel · Posted: Mon Feb 27, 2012 4:32 pm Post subject:

woodburner · Joined: 06 Apr 2009 Posts: 1459

You may find interesting things when running on veg oil. I have seen injector pump damage from a veg oil session. That cost £2000 to fix.

If you are going to do wood heating, have look at masonry stoves, russian fires, and rocket mass heaters if you haven't already.

www.rocketstoves.com the book is worth downloading.

Dave K · Joined: 23 Feb 2012 Posts: 2 Location: Hertfordshire

Thanks for the info about getting started on veg oil. It is quite a big thing to change from your regular (at the pump) fuels to something that is reasonably green.
I had thought about maybe going for a Land Rover, I'll have to keep scouring the Internet for suitable cars.
Does anyone know of a good website for already converted veg oil cars? I've found a site call car ocean that has a few, but I'm not sure in google that I'm looking in the right place?

JavaScriptDonkey · Joined: 02 Jun 2011 Posts: 1474 Location: SE England

woodburner · Joined: 06 Apr 2009 Posts: 1459

I don't think using oils produced by western style agriculture is green at all. There is a large fossil fuel input, and the EROEI (if that's spelt right) is not very good, maybe 1.5:1. If the oils come from palm oil it's an environmental disaster.

There is a lot in the fuel from the pumps to ensure long life for engines. That won't be the case with homebrew. Long stroke, low stress engines will work ok, modern high stress car engines I doubt will survive so well.

Tarrel · Posted: Mon Feb 27, 2012 11:15 pm Post subject:

@javascriptdonkey:

Do you have any views or experience on the normally aspirated 2.5 diesel? (ex military).

JavaScriptDonkey · Joined: 02 Jun 2011 Posts: 1474 Location: SE England

Tarrel · Posted: Tue Feb 28, 2012 9:51 pm Post subject:

Yes, I've heard they're a little on the slow side. That doesn't bother me though, given the use I'll be putting it to. I wonder how it would be on a 50/50 mix?