Just out of interest really.. I was wandering what would happen if I put varying quantities of ethanol in my Mk3? I've had a bit of a read and I understand that just chucking E85 (85% ethanol-available at my local morrisons) probably isn't going to be too good for my engine. But most cars in the US since the late 80's have been able to take 10-20% ethanol fuel mixtures and I figure that VW would probably make sure their entire range was capable of that (my logic may be very misguided though).

A tank of petrol is 42 litres so 10% of that is 4.2 litres meaning that I'd need 4.94 litres of E85..

Anyone interested in knowing what happens in terms of performance and fuel consumption or want to tell me that it's sheer madness and my engine would go bang and make me die?

cheers

Ben :)

Expect your fuel consumption to increase with an E85 blend. Don't be tempted to go too high on the ethanol content, it's not good for the seals in the injectors and fuel pumps, and probably not too good for the fuel lines either. If you're serious about running high ethanol contents, you need to sort the fuel components and get a remap.

Go and buy some Tesco 99RON fuel - they've already done the work for you, with a 5% ethanol blend. I've tried both my G40 and my Saab Aero on it. Both seem to go about as well as they do with V-power, but both return poorer fuel economy. ( Approx 30mpg vs 34mpg for the G40, and 25mpg vs 28mpg for the Saab).

I would imagine that the fuel system should take it OK. VW has OK'd biofuel usage for a very long time. I've had a bit of experience with veggie oil on diesels and VW were way ahead in picking the right materials to withstand the effects.

Veggie oil is quite different to ethanol... Ethanol is very corrosive.

And one of the biggest car suppliers in Brazil is..........

And your point is? That in the early '90s VW were over engineering their cheapo, European market only, built in Spain shopping trolleys, so that they could run on ethanol? Their Brazilian market vehicles use very different parts on the whole.

By all means go and run YOUR car on pure ethanol if you're so sure. If your theory is correct, why are so many manufacturers using different fuel systems for their E85 vehicles?

I'm not saying anything about the fuel merely that VW probably have more experience in this area than most manufacturers.

Edited 3 February, 200719 yr by yeha

I've seen what 110RON can do to an engine (pikies nicked a drum of fuel out of my mates truck, little did they know it was for his stock car), I'd say 107 is tempting fate a little too much.

Ok.. So maybe this is an old thread but still. These are my experiences with E85.

I have been runnin two BMW 728 -96 on 100% ethanol for over 40000kms, I have been running one Audi A6 2,7Bi-Turbo Quattro -00 for over 20000kms on 100% E85, I have been running one Vauxhall / Opel Frontera A -96 on 100% E85 for I dont know how long now. A friend of mine wanted me to get his Volvo 850 -96 to run on E85,so I did.My next project will be my 1990 Polo 86C.

What I have learned.

The bad things:

Well I had to install a piggyback system on all the cars called Flexitune. On the Audi it took a complete day to install. On the BMWs it took about 3 hours, on the Frontera and Volvo it took about 15 minutes.

I had a fuel hose leak on the Frontera, but after inspecting the hose I could see that it was'nt the E85 fault.

On the BMWs the fuelconsumption increased with about 40%, on the Audi about 30%, on the Opel about 45% and on the Volvo about 10%

After driving with E85 for about 2000kms it was recommended to change the fuel filter and it's recommended to change the oil and oilfilter every 10000kms.

The good things:

Even tho it consumed more it was easier on my economy.

I loved the fact that the cars was running better on E85, especially the Audi

Its betterfo the environment.

Love the smell from the exhaust

Got a cleaner engine (looked at the sparkplugs and they looked like new after driving 30000kms)

Good to know:

If the car is older then -96 you shold check your hoses

Nothing har corroded on my cars yet

I fueld up my Polo -90 with 50/50 the other day, worked fine.

Well.. that about it in short terms. I love E85 as you may understand by this. If you have any questions dont hesitate to ask.

If you would like to try driving on E85, start at mixing in about 20% and see how it goes. And then increase to 30%.

I gave these instructions to a friend with and old Mercedes. I told him, use 10% and the increase. I put in 90% and gues what; his car would'nt start the next day...So go slow.

//parikh

Good info!

Presumably the fuel filter gets changed regularly as the ethanol scours the fuel tank so frees up a lot of dirt? Do you get problems with water in the tank? Does the E85 available in Sweden have any additives, or is it pure ethanol?

Have you had any problems with fuel pumps or injectors at all? I damaged an old fuel pump by running methanol in my G40.

no mention of altering timing. or is this just because the fuel is cheap, and not for extra power ?

by all accounts, increasing the octane to over 110, with no other changes, should loose you power and economy, due to slower burn rate.

So who sells it?And why do they sell it - what is it sold as?

You can buy E85 at the pump in certain Morrisons petrol stations, or the 5% ethanol blend at most Tescos that sell 99RON juice. Have seen ethanol advertised on eBeg too!

Alcohols aren't that corrosive to plastics or rubber. I think its more a case of them exploiting old perished lines due to them being smaller molecules than heptane, the main constituent of petrol. Screenwash is isopropanol don't forget. Aromatic hydrocarbons (eg toluene - methyl benzene) on the other hand will degrade plastic and rubber no problem! I have heard this being used somewhere as a fuel additive.

Unfortunately you can't go sticking e85 in an older polo and forget about it, otherwise i'd have no 2nd year project

Despite some crap info available on the interweb I've gone by case studies from various manafacturers and Uni studies into converting cars to use the fuel.

Ideally you want to increase the compression ratio to increase the engines thermal efficiency, due to the nature of E85 (higher octane) you can get away with it alot more than petrol (ideal for turbo'd cars then )

Plugs will depend on your application, higher compression would mean a colder plug, but on ethanol you actually want to go hotter.

Alcohols aren't that corrosive to plastics or rubber.

Erm, quite alot of people would disagree with you nick... they degrade in the presence of ethanol, apprently need to be replaced with Viton which has a decent resistance to permeation and good resistance to heat and swelling.... but not cheap.

Depending on your fuel cell/tank type you may also need to change this, i was going to use an ally tank, but ethanol is most corrosive acting as an electrolyte in a galvanic corrosion environment- i.e ally will corrode, so any fuel rails, fuel tanks (and possibly inlet manifolds and heads- but there contact with the fuel is brief) will need to be changed.

Basically if you have anything that touches the fuel made from brass, zinc, lead or ally, you're in trouble. Now think of fuel pumps, filters, lines, fuel rails, spark plugs.

Alot of manafactures' stuff WILL work, but ask GM if any of their non ethanol specific cars have ethanol complient fuel systems, the answer will be no Unless your car came with teflon braided lines that is...

You could however either get custom parts made from ally and then anodize them (a route i'm considering) or get stuff made from stainless steel... either way it not cheap, that's just a small section of the conversion, you've got to think about mapping etc after that- i'll be using megasquirts newish 'flex-fuel' software so i can run a mixture of ethanol and petrol, as and when i can get the fuel.

You can run the E85 on your origional system, but in time you will get a build up of a crystal like deposit that looks like brown suger, so you would need to flush your system every now and then, which is a pain to do if you use the car everyday or as Yoof says:

You could however either get custom parts made from ally and then anodize them (a route i'm considering) or get stuff made from stainless steel... either way it not cheap, that's just a small section of the conversion, you've got to think about mapping etc after that- i'll be using megasquirts newish 'flex-fuel' software so i can run a mixture of ethanol and petrol, as and when i can get the fuel.

well that is alot of information... Certainly interesting to read about and I'm glad I've provoked a bit of discussion :)

I guess I'll leave it for now, I was just intrigued as to the effect that it would have. I think I may need to read the thread again when I'm a little more awake because I'm sure I haven't taken all of that info in.

cheers guys

Ben

UP!

Does anyone tried E85 in his Polo recently ?

I decided against it in the end, I don't think my engine would really benefit that much because all E85 really does is have a high octane and burn really quickly..