# Anyone tried running their TDI on Cooking oil?



## tortoise99 (Dec 26, 2005)

Have owned my lovely 225 MK1 for 7 or 8 years. However thinking of chopping it in for a MK 2 TDI at some point over the next few months.

A friend of the family owns a diesel car (ford or vauxhall I believe), and claims he is running it on cooking oil purchased from the local supermarket, not 100% but say 70% diesel, 30% cooking oil. I'm sure he's paying the duty on the oil :wink:

Anyway, anybody tried cooking oil in their TT TDI? Any problems? What are the pros & cons?

Thanks


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## Philplop (Nov 22, 2011)

How old is their car?

You can do it on old diesels, but not new ones.

Don't try it!

Pretty sure you don't need to pay fuel duty on cooking oil until you're using more than a certain amount per year, and it's a decent amount too.


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## phil3012 (Jul 25, 2008)

When I bought mine the dealer warned me not to, think it says something about it in the manual as well.


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## Bikerz (Aug 23, 2008)

2,500 liters free a year. Dont even bother on a new TDI! Not worth it, if you can afford a TDI TT you can afford the fuel. Get somthing old for veg, 1.9SDI work well on it or any pug dirty D's or Merc D's that are old. (Ive done it)


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## Smeds (Oct 28, 2009)

I had an N reg Golf tdi, used veg oil in it sometimes, about 60% diesel to 40% veg in the end it is potentially what killed the fuel pump, but the car cost me £800 and lasted 13 months.


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## Gone (May 5, 2009)

If you do it, do it properly. We want to see vagcom logs, cost and fuel economy plots, and spreadsheets.


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## rob.b (Feb 11, 2011)

It definately says in the manual NOT to run on vegetable oil! It goes far enough on diesel, so why bother?


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## mighTy Tee (Jul 10, 2002)

First of all take the car to a tuner and get it "chipped" :lol:

Seriously though modern high pressure diesels rely on diesel lubrication and very fine filtering to work correctly and with a replacement diesel pump costing mega-bucks it is not worth the risk.


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## audimad (Jan 7, 2008)

What a stupid question, i can't believe you are even thinking it! [smiley=freak.gif]


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## newt (May 12, 2002)

For gods sake WHY :x


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## Philplop (Nov 22, 2011)

It's not that stupid a question. Some diesels run fine on vegetable oil.

And why? How about because it's loads cheaper?


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## BarrieB (Aug 24, 2011)

Maybe we can try doing it the other way round by frying some chips in Diesel. Should produce some interesting results!


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## mighTy Tee (Jul 10, 2002)

Philplop said:


> It's not that stupid a question. Some diesels run fine on vegetable oil.
> 
> And why? How about because it's loads cheaper?


At several thousand pounds for a new high pressure diesel pump, take it from me* manufacturers will not allow modern high pressure diesel engines to be sold in some countries because the quality of the diesel will f**k up the pump. Therefore cooking oil will be a definite NO.

*_It is part of my job_


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## Philplop (Nov 22, 2011)

Yeah, fair enough, but as has been said, some older cars are fine on cooking oil, so it's not such a stupid question as people are making out.


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## TortToise (Aug 22, 2009)

Philplop said:


> It's not that stupid a question. Some diesels run fine on vegetable oil.
> 
> And why? How about because it's loads cheaper?


_Old_ non-turbo diesels will run on a wide variety of stuff.

But one of the reasons why modern high performance diesel engines give so much power is because they are optimised for actual diesel fuel. Older, usually non-turboed, designs were a lot more forgiving of fuel source (and lower performance).

Putting veg oil in a modern unit is a surefire way to trash the engine. Bio-diesel might work as part of a blend with diesel but the car makers seem to have gone off that idea in the last couple of years. If I had a TT TDi I certainly wouldn't risk it.


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## m-a-r-k (Nov 17, 2009)

The manuals for all VAG diesels specifically and clearly state not to use biodiesel fuel so I imagine they would have a fit with chip fat!


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## TT-TOM (Feb 15, 2012)

go to the tdi club forum and get some advice, there seems to be a few on there that do it.

The 2.0 common rail engine has enough high pressure fuel pump failures when you run them on diesel, nevermind bio our cooking oil.

The reliability of modern diesels and things like diesel particulate filters is one of the reasons I bought my TT instead of sticking with diesel. you just never know when your tdi is going to implode and cost you a few thousand pound.

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## wja96 (Mar 4, 2010)

TT-TOM said:


> go to the tdi club forum and get some advice, there seems to be a few on there that do it.
> 
> The 2.0 common rail engine has enough high pressure fuel pump failures when you run them on diesel, nevermind bio our cooking oil.
> 
> ...


I've had nothing but VAG diesels for the last 7 years/300,000 miles and I'm on most forums and apart from DPF issues on most later PD cars and injector failures on some PD140's I'm not aware of any major reliability issues with them. Certainly not on the CR engines.

The TDi TT is roughly 4 years old and there's not a single post on here with regard to an engine failure, DPF failure or HPR pump failure. Pretty much everything mechanically problematic on TTs is related to the S-tronic gearbox. Coil pack failures on 2.0 petrols, yes. Haldex failures after bad servicing, sure. But nothing on diesels. They seem to be boringly reliable.

Now, if you'd said that you couldn't understand why anyone would buy a diesel now the fuel economy is so bad and the 2.0 TFSi has 350Nm of torque and 40bhp more then you'd have an argument, but diesel reliability? No.

Badly remapped diesels implode, certainly, but that's why I get mine done at Shark Performance.


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## TT-TOM (Feb 15, 2012)

wja96 said:


> TT-TOM said:
> 
> 
> > I've had nothing but VAG diesels for the last 7 years/300,000 miles and I'm on most forums and apart from DPF issues on most later PD cars and injector failures on some PD140's I'm not aware of any major reliability issues with them. Certainly not on the CR engines.
> ...


You don't need to preach to me, I'm not bashing diesels at all, i'm very much still a diesel fanboy myself, my area of expertise is the VAG 1.9 TDI, most things i've ever done on cars has been to do with that engine in the whole range of VAG incarnations so i know how reliable they are, how well they drive and the economy. In fact they wipe the floor with most other non German diesels.

However you need to look at this list:

http://forums.tdiclub.com/showthread.ph ... p+failures

Look at how low the milage is on the cars which had their HPFP detonate on them. You can't really argue with that list. I mean its actually BOSH at fault i think as they make the fuel pump, and hopefully they have sorted the problem in the TT. But when the Passat came out they had that many failures they couldn't keep up with the demand of new pumps and they were lining up outside the dealers waiting for parts.

I would own a PD TDI any day of the week, but move to a 2.0 common rail. No thanks, maybe if i was doing 20k it may be worth it as thats probably enough milage to keep the DPF happy and save a lot on fuel. But for 10k a year average Joe's the risk isn't worth it.


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## wja96 (Mar 4, 2010)

The TT and most European VAG CR170s use the CBBB engine, so not covered by that thread. And it looks like at least half those posts were damaged by using the wrong grade of fuel. Do you have anything from Europe? You made a pretty big assertion there - you won't buy a diesel TT because it would blow up and cost £1000's and I'm sorry, but I simply don't see ny evidence for it.


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## TT-TOM (Feb 15, 2012)

I'm not saying that it will blow up. There are plenty about and probably millions having trouble free motoring with the 2.0.

I'm saying they are more complicated and expensive if it goes wrong and that petrol engines have overtaken diesels in terms of reliability. For one they don't have horrendously expensive injectors and they don't have a hpfp that costs a few grand.

Which is the reason why i decided it wasnt worth buying a 2.0 cr diesel as I'd rather do 30 mpg than worry about it going wrong.

I'll try and find out where I saw the article on the passat problems


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## BarrieB (Aug 24, 2011)

On the subject of fuel type, does anyone know if the use of premium diesel as opposed to standard diesel have any long term effect on reliability, either good or bad? There have been many threads about mpg and performance but not much on reliability. What impact is there on the DPF for example?


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## wja96 (Mar 4, 2010)

TT-TOM said:


> I'm not saying that it will blow up. There are plenty about and probably millions having trouble free motoring with the 2.0.
> 
> I'm saying they are more complicated and expensive if it goes wrong and that petrol engines have overtaken diesels in terms of reliability. For one they don't have horrendously expensive injectors and they don't have a hpfp that costs a few grand.
> 
> ...


There was a batch of duff fuel pumps on early CR140 Passats but that was resolved. I'm not aware of any current issues with TDi VAG engines.


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## phil3012 (Jul 25, 2008)

There has been a recall on the earlier TDis by the way also I had one of the sensors go and needed replacing.

Has been spot on apart from that though.


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## TT-TOM (Feb 15, 2012)

wja96 said:


> TT-TOM said:
> 
> 
> > I'm not saying that it will blow up. There are plenty about and probably millions having trouble free motoring with the 2.0.
> ...


This is what I'm probably thinking of.

But regardless of my opinions, I wouldn't be putting cooking oil or bio in a modern diesel

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## rob.b (Feb 11, 2011)

BarrieB said:


> On the subject of fuel type, does anyone know if the use of premium diesel as opposed to standard diesel have any long term effect on reliability, either good or bad? There have been many threads about mpg and performance but not much on reliability. What impact is there on the DPF for example?


I have owned my R reg Mk4 90 hp TDI Golf since it was new. I have just looked and it's now on 225,063 and during that time I have never put anything in except "normal" diesel, usually frome Tesco. It gets an oil change /service when it indicates, and overall it still averages 50 mpg, so I would say that using "expensive" diesel isn't really worth it. I have also never had any problem whatsoever with the fuel pump or the PDF! Rob


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## wja96 (Mar 4, 2010)

TT-TOM said:


> But regardless of my opinions, I wouldn't be putting cooking oil or bio in a modern diesel


No, I have to say that if the 2011 MY 2.0 TFSi engine had been available when I got my TT I would probably have had to think very hard about whether the extra fuel economy was really worthwhile. My car is now basically the same performance as the petrol but better on fuel economy, however, the petrol with a remap is almost into TTS-bothering territory. And the fuel economy probably isn't that much worse than the diesel in the real world, especially if you are asking progress on A roads.


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## mark_1423 (Dec 13, 2011)

i wouldn't put it straight in, i run my van on bio diesel what is a turbo i know its a van not a car. in the summer we run it on neat, winter 50/50 as it goes a little stiffer in the cold. if your going to try it mate i would get your self a processor and make it. i heard diesel in the pumps now days has bio diesel in it anyway but how much i don't know.


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## TT-driver (Sep 14, 2010)

wja96 said:


> There was a batch of duff fuel pumps on early CR140 Passats but that was resolved. I'm not aware of any current issues with TDi VAG engines.


Colleague of mine went through 3 turbo's on his 2007 140 BHP 2.0 TDI in an A3. My sister in law, same issue in her VW Eos. And quite a few of the first 2.0 TDIs suffered from cracked cylinder heads resulting in coolant loss. Not sure if all these engines are actually the same as the one currently mounted in the TT though...


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## wja96 (Mar 4, 2010)

mark_1423 said:


> i heard diesel in the pumps now days has bio diesel in it anyway but how much i don't know.


It's up to 10% I think.


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## TT-TOM (Feb 15, 2012)

BarrieB said:


> On the subject of fuel type, does anyone know if the use of premium diesel as opposed to standard diesel have any long term effect on reliability, either good or bad? There have been many threads about mpg and performance but not much on reliability. What impact is there on the DPF for example?


Premium diesel is supposed to be better for the engine as it Burns cleaner and helps reduce soot build up. quite important in diesels with vnt turbos where the nozzles can seize causing overboost. I can only see it being better for the dpf if making any difference at all

I found I got more mpg with it but it did not outweigh the cost.

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## TT-TOM (Feb 15, 2012)

wja96 said:


> mark_1423 said:
> 
> 
> > i heard diesel in the pumps now days has bio diesel in it anyway but how much i don't know.
> ...


I don't think it his bio in it unless it states its bio. I think 10% bio to 90% diesel is called B10. I've never seen anywhere that sells it.

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## wja96 (Mar 4, 2010)

I'll see if I can get a picture of the pump label next time I'm filling up. It definitely says something like "contains up to x% biofuel".


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## r_youngson (Apr 29, 2009)

wja96 said:


> I'll see if I can get a picture of the pump label next time I'm filling up. It definitely says something like "contains up to x% biofuel".


The last I saw it was 7%, although there may have been an increase since then. It used to be 5% but the government increased the required content. The manual says something about using no more than 5% biodiesel in your car but I'm guessing that means adding 5% separately(?) as any fuel sold at the pumps will have to meet a certain specification.


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## newt (May 12, 2002)

r_youngson said:


> wja96 said:
> 
> 
> > I'll see if I can get a picture of the pump label next time I'm filling up. It definitely says something like "contains up to x% biofuel".
> ...


Yes I doubt it is chip fat


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## r_youngson (Apr 29, 2009)

newt said:


> r_youngson said:
> 
> 
> > wja96 said:
> ...


Of course not.... at least not anymore. Vegetable oil and biodiesel are quite different things. For fuel usage, vegetable oil is usually referred to as SVO (Straight Vegetable Oil) or WVO (Waste Vegetable Oil). Only when you chemically convert SVO or WVO, or whatever suitable waste liquid fat you can find, do you get biodiesel.

Doubt you'll find any manufacturer recommending the use of vegetable oil (personally I wouldn't put vegetable oil in any diesel car unless it was pretty much worthless to start wth), but biodiesel is processed and treated to certain standards for use as a fuel and there are cars out there which the manufacturers say are compatible for use with 100% biodiesel so with the right car you could save a lot on fuel... especially if you have access to cheap/free waste oil for making your own biodiesel. VW don't approve more than 7% biodiesel in diesel fuel for the current range of TDi's, as of April 2010 (previously 5%), though some of the older VW/Audi/Seat/Skoda TDis are either compatible with 100% biodiesel or can be upgraded to be so. 
The following link might be useful for anyone with an older VW/Audi TDi considering the use of biodiesel: 
www.volkswagen.co.uk/assets/common/pdf/ ... diesel.pdf


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## Bikerz (Aug 23, 2008)

Philplop said:


> Yeah, fair enough, but as has been said, some older cars are fine on cooking oil, so it's not such a stupid question as people are making out.


IT IS!

Do you have any idea about the fuel pressure a old mer D or 405 D works on and a new TT? Have a look and your find you answer pretty quick


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## Bikerz (Aug 23, 2008)

wja96 said:


> TT-TOM said:
> 
> 
> > I'm not saying that it will blow up. There are plenty about and probably millions having trouble free motoring with the 2.0.
> ...


It was the 170's & 140's that had the dodgey pumps. Mums passat and my golf 170 had new ones under warrenty


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## Bikerz (Aug 23, 2008)

TT-TOM said:


> wja96 said:
> 
> 
> > mark_1423 said:
> ...


Correct! Its a legal requirement in the ALL D that you buy at the pump will be 10%. The gov are trying to increase this with huge problems to car manufactures.


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## Wallsendmag (Feb 12, 2004)

Does it have to be new or can you just empty the fryer ?


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