Both of my vehicles are turbo diesels, and I was just wondering if, in a pinch, I could put vegetable oil in the tank without ill-effect.

Is it possible? What potential problems could ensue?

Bit more info might help. Age, model etc.
I havent got a clue , but it will help someone who has a bit of knowledge

If it’s from this* century almost certainly no.

*As in post 2000 for the wisecrackers.

I wouldn’t do it unless I had no alternative.

https://choosesq.com/blog/how-to-run-a-car-on-vegetable-oil/

2008 Jaguar X-Type 2.0
2013 Mercedes Vito 2.5

But I’m assuming the precise type of vehicle doesn’t matter too much, assuming they’re both pretty much bangers now that are going to be driven until they’re dead.

It’s not likely to go well. I used to do this successfully in summer time with non turbo diesels back in the day – cars that would be 20+ years old now. Straight veg oil was generally only a success in simple engines, but you had to watch out for melting seals in some models of fuel pumps etc.
Generally veg oil is to viscous compared to diesel to work in modern diesels (last 10years plus) without major modification.

Thanks, @thols2. That pretty much answers my question.

Old fashioned vehicles with a mechanical pump? Yes, but I’d not bother.

Newer vehicles with a common rail (or VAG group PD engines)? NO . . .NO. Pointless exercise frankly. What would you gain?

What would you gain?

Vegan bragging rights?

More Miles Per Gourd?

Decreased Legumes Per KM?

What would you gain

Fuel in a crisis*:

* Media fueled shitstorm non event.

If it all goes mad Max it’ll be heating oil mixed with chainsaw bar oil here but my engines 35 years old- but I’d have to be pretty desperate to get somewhere before that happened.

I was just wondering if, in a pinch, I could put vegetable oil in the tank without ill-effect.

No. I read up on this at length years ago.

But I’m assuming the precise type of vehicle doesn’t matter too much

It does, for a whole load of technicl reasons. I could go into it if anyone wants.

assuming they’re both pretty much bangers now that are going to be driven until they’re dead.

I’m guessing you’d rather that was in 50,000 miles time rather than 500 🙂

Absolutely, @molgrips!

The Jag just keeps passing it’s MOT with no issues. It’s actually an incredible car that I would like to keep running for a long time to come.

I find the question about vegetable oil interesting because there was an apocryphal story of a guy with a 1980s Volvo in British Columbia who ran out of diesel, but managed to run the car on v.o. until he could get to a station. He then developed a refinery for used oil in his garage.

1980s Volvo in British Columbia

Big advances in diesel technology between the 1980s and both your car’s means that it’s no longer a thing.

Won’t atomise at the injector properly and will wreck pump seals

Course ypu can. There is some bio in alot of deisel already.
Whether it will last thousands of miles is another story
You cpuld probably add 25% veg oil amd it would be fine all summer
I did thousands of miles in a xud engined citroen zx, so mechanical injection
The oil has to be hot to be the equivalent viscosity of deisel, so a twin tank system and 3 way changeovr valve is required
You start on deisel, drive 4 miles then switch ovet, an inline heat exchanger plumbed in to the heatet matrx feed line warms the veg oil
Then 1 mile or so from destination you switch back to desiel
So upon cold starting the pump and injection system is full of deisel again
There is a weird thing where the veg oil picks up and holds all the crap in ypur tank amd transports it to your fuel filtrt, but this only happens once and then you breakdown, swsp filter amd your off again
Would i run a hp cr modern engine on it, nope, but i would add a little and expevt it to be ok at low percentages

If it all goes mad Max it’ll be heating oil mixed with chainsaw bar oil here but my engines 35 years old- but I’d have to be pretty desperate to get somewhere before that happened. my tank of heating oil will have long since been plundered by Tina Turner and road warrior motorcycle gangs in chaps and my fingers taken by a metal boomerang

Ftfy.😉

If using vegetable oil is possible, you’ll be able to tell because there won’t be a drop of it on the shelves anywhere if this goes on a bit.

I had a friend that ran his Volvo on used veg oil, his was almost free in that he collected it from restaurants, had a processing tank in his garden, you need additives to work properly, but he had no fumes, smelt like a deep fat fryer and the cost saving was pretty big.

New oil out of the supermarket? no and it would cost more anyway, that would be taking panic buying to a whole new level.

I used to run an old smiley face type Transit on almost SVO. Old non turbo engine with no power. Started with with a little bit and waited for it to die but ended up running about 90% veg at all times. Straight from the bottle when it was 48p a litre. Not sure what the price is now but probably not much less than diesel.

Never had the nerve to try it on my T5.

I find the question about vegetable oil interesting because there was an apocryphal story of a guy with a 1980s Volvo in British Columbia who ran out of diesel, but managed to run the car on v.o. until he could get to a station. He then developed a refinery for used oil in his garage.

This entirely plausible.

Hot veg oil is of a similar consistency to diesel. So you can pump it and squirt it out of a tiny hole into a combustion chamber just like you do with diesel. It’s also just as good for lubrication if not better.But it gets thicker as it gets colder and veg oils ‘freeze’ or turn to gel at much higher temperatures than diesel, for some the gel point is -10C and for some it’s +5C. That’s why some people used to run ‘twin tank’ systems as singletrackmind described.

But there are other issues. If the oil is too thick then when you inject it directly into the combustion chamber it forms bigger droplets and it might not all burn, and then it ends up on the cylinder walls or forced past the rings where it ends up in the engine oil. Above a certain percentage of veg oil at the high temperatures of the engine oil it will suddenly polymerise – like when you get oil vapour collecting on the cooker hood in the kitchen and don’t clean it up and then you can’t get it off. Some mechanics reported dropping the sump and seeing the whole crankshaft encased in jelly.

Very old diesels not only have a mechanical injection pump but they also don’t inject the fuel directly into the cylinder, they have a swirl chamber where the hot compressed air comes in, swirls around with the injected fuel and ensures really good combustion. This means you don’t have the above problem and yes, you can just pour veg oil into the tank and drive around, as long as your oil doesn’t freeze. I did this for a few years in a 1994 VW Passat (what else) 1.9 TD, as distinct from the TDI. The I in VW terms means direct injection i.e. no swirl chamber. Later engines still had a mechanical pump but they were direct injection and less suitable for running on veg oil.

You can refine veg oil, used or not, into biodiesel which has much better viscosity but it does still cause the engine oil to polymerise if enough gets into it. This generally won’t happen unless you have a certain type of engine with a DPF. Some engines have a fifth fuel injector that squirts fuel directly into the exhaust manifold so the catalyst heats up the DPF to burn off the soot; whereas others inject fuel into the main cylinder during the exhaust stroke which has the same effect. Unfortunately this also results in biodiesel on the cylinder walls that doesn’t get burned and ends up in the sump, and you have a jelly problem again.

There can also be problems with biodiesel and some rubber components in the engine, but it’s not clear when manufacturers used what type of rubber so on some cars it’s a lottery if 100% biodiesel is going to ruin the seals and hoses or not.

In short, with your two cars, don’t do it.

Re collecting used veg oil – you can’t do this any more as companies have realised it has value for refining into biodiesel. Chippy owners used to have to pay for it to be taken away, now they get money for it.

Sod veg oil…I’m going for lard…

You can use lard, it has lots of energy, as long as you can heat it up well enough.

Hmmm

So due to the current madness I had to queue to fill my car with the only available diesel – HVO diesel.

I understand it’s liquid chips, or at least smells like it but is it likely to flip my 2010 Mundane-o ?!

I used to run my 1997 smiley-face Transhit on refined veg oil. Cheap as chips, slightly worse economy and it puffed out smoke rings at idle.

I used to buy it off ebay.
Scored 500ltrs in 5ltr bottles when spme racking collapsed in a warehouse
Was like 25p a ltr, all boxed with oil on the labels making it unsaleable
Never tried to clean it from the chippy, meth oxide washing and triple filtration required for that malarkey
Still smelt like a chippy tho.

Glycerol will knacker your engine, proper biodiesel has been esterified to remove it. It’ll run but it won’t do it any good

For all those admitting using it up there^, presumably you declared it and paid the necessary duty?

Grandad mode off… 😊

presumably you declared it and paid the necessary duty?

IIRC there was a limit of usage below which you didn’t need to.

IIRC there was a limit of usage below which you didn’t need to.

Iirc it was 2500l which is about 25000 miles possibly more in a TD Passat.

Recycling a boot full of 25l oil drums caused some issues at the tip when they thought it was commercial waste. They didn’t believe I was running my car on it until a gust of wind blew the smell over from the exhaust.

So the conclusion to be made from this thread is we need a FB meme about running cars from vegetable oil to remove a whole block of idiots from the road!

got this from one of my customers:
ALDI opened in Kirkwall Orkney islands around the time of the 2007 fuel protests, and had opening offers – one of which was bottles of veg oil at something like 40p/litre. local plumber driving an old VW van bought the entire pallet and ran his van very cheaply that summer. He said there wasnt any issues with the van but he wanted chips all day!