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schneil

E10 petrol

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schneil

If you've been to the petrol station recently, you'll have noticed the labelling of unleaded and diesel has changed. The new labels are E5 and B7 for petrol and diesel respectively. 

 

https://inews.co.uk/essentials/lifestyle/cars/car-news/petrol-pump-labels-changed-what-you-need-to-know/

 

So E5 petrol contains 5% ethanol, B7 is 7% biodiesel. 

 

The government is considering introducing E10 petrol, but the RAC research says older Volkswagen golfs are not compatible..

 

Would our old Polos be ok?

 

 

 

 

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kwijibo_coupe

Depends on the age of the Polo.

Anything before 1990 still using a carb should really stick to just petrol and I'd say the same for early injection models too as they aren't 'clever' enough to adjust the parameters for the change in fuel quality or mixture.

Likely Polos from the 9n onwards should be fine though. 

 

I wonder if this is the start of the government literally forcing us into newer cars. 

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dvderlm

2 years of 5% Ethanol Momentum99, plus water in the fuel from pin-holed rusty fuel tank neck (and vent to atmosphere not carbon canister.)

Blocked my carbs.

 

On the plus side you can run more ignition advance and avoid knock.

 

You'll need to add Ethomix or similar to keep moisture away.

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zob
On 16/09/2019 at 08:25, dvderlm said:

You'll need to add Ethomix or similar to keep moisture away.

 

In your opinion is this likely all most of us will need to do? I've read that the gonvernment was consulting to 'force large vendors to offer E5 alongside E10' but it looks like that was done under Grayling so I won't hold my breath!

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dvderlm
11 hours ago, zob said:

 

In your opinion is this likely all most of us will need to do? I've read that the gonvernment was consulting to 'force large vendors to offer E5 alongside E10' but it looks like that was done under Grayling so I won't hold my breath!

On pre 1990 car, yes, I hope so. 

On a carb, small adjustment to idle, slightly larger main jet, small advance to timing is probably sufficient to achieve optimal running (plus moisture precaution especially if not driven regularly).

Though ethanol is. not kind to brass, so twin weber DCOE may suffer. No issue with Pierburg, Weber DMTx or others with plastic floats. Dunno what Solex PICT uses.

My dellorto floats are nitrophyl so safe. 

 

Painting the float (with thinned POR15 or similar epoxy paint) will stop it being eaten and be the few percent heavy to let it have less freeboard for less dense fuel.

(or the tang can be bent downwards)

Either of these actions is probable new carb gasket and rubbers kit time.

 

As for EFI.

I need to understand why a Vw Polo from 2000 won't work on E10 or how E10 may cause damage, but Seat Ibiza from 2002 onwards is fine.

Was Spanish fuel already bio-based back then?

I imagine no engine management change, upgrade or compensation is possible for the changed combustion properties.

 

The RAC data is mostly statistical, but draws on manufacturer compatibility coding declarations

and assumes people will carry out recommended manufacturer mods if they exist ( a big if ) .   

https://www.racfoundation.org/wp-content/uploads/The_impact_of_E10_final_Wengraf_July_2018.pdf

 

(i must try and find a Porsche Model Missing in Practical Classics). 

Edited by dvderlm

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dvderlm

Oh yeah, carb needle valves are usually brass. Maybe okay up to E10 concentration. They are a wear component, so it's hard to know if ethanol or wear is cause of any anecdotal reported leakage.

No it is okay page 14 of Tomkins dissertation says brass is safe in Ethanol.

 

but water in the fuel is bad 

 

 

 

Edited by dvderlm

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dvderlm

Really good info here

 

https://www.iea-amf.org/content/fuel_information/ethanol/e10/e10_compatibility#ethanol_cars

(was Seat Ibiza sold in Brazil)

 

Oh yes, vapour forming, using Momentum99 in July I found I had to insulate my fuel line from heat, but that might be a coincidental vacuum leak.

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dvderlm

"First-generation direct-injection fuel systems with aluminum rails do not tolerate ethanol (ETP 2011). Corrosion product of aluminum forms a gel" might explain the Vw 2000 era incompatibility. 

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zob

Interesting, albiet concerning, stuff. I suppose the question for most people with older vehicles is going to be the availability of E5 and whether or not we're going to be forced into buying 'fancy' unleaded just to avoid the higher percentages of ethanol. I'd be relatively ok with it if all I had to change on my '93 Mk2f were fuel lines, filters and o-rings but the problem of water absorbtion and separation in cold temperatures is concerning - how is a modern car supposed to handle that?

 

Light aircraft owners using modified aircooled petrol engines have long known about the dangers of ethanol - i remember my instructor telling me to watch out for water separation when checking fuel contamination. You pop a little flask over a valve on the tank or carb and draw out a sample to be checked visually for water droplets but if the bottom of the tank is all water you can easily mistake it for fuel (smells like fuel too!). Surely we would all need fuel filters with a water trap to be checked periodically?

 

11 hours ago, dvderlm said:

Really good info here

 

https://www.iea-amf.org/content/fuel_information/ethanol/e10/e10_compatibility#ethanol_cars

(was Seat Ibiza sold in Brazil)

 

Oh yes, vapour forming, using Momentum99 in July I found I had to insulate my fuel line from heat, but that might be a coincidental vacuum leak.

 

Thats an excellent article - thanks for the link.

 

I wonder what the experience in France has been like since the introduction of E10? I always see heaps of '90s cars around when I visit, but perhaps they're mostly diesel?

 

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dvderlm

i think there are different ways of blending in the ethanol and it can be more oxygenated. Perhaps France has different blend.

Needs more research. 

 

Water in my tank might have been rain dripping in higher pinholes than the petrol dripped out, but I think it was just the very long period car mostly stood with not much fuel autumn to spring.

It's vent to air tubing was dodgy state so no inverted loop connected which might work as simple vapour trap.

 

Modern (90s) cars have unvented tank with carbon filled capture canister for petrol/ethanol vapours. Damp air should not get in - even when filling you'll notice the trapdoor for the nozzle.

I always thought it was to stop mis-fuelling with diesel, but now I'm not so sure.

 

The canister stops evaporative emissions harming environment , the vapours are let into combustion once engine warmed and some people delete them.

Maybe French MOT checks you have not done that? Guess.

If it's an open tube as the petrol goes down, (possibly damp) air gets sucked in.

But surely people plug the tube when they delete the canister?

 

 

 


 

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caretakerplus

I have no idea if it is still used, but petrol stations used to check their storage tanks for water contamination with a paste, supplied by the oil company.

This green paste was applied to the end of the tank dip stick, the dipstick placed in the tank and immediately pulled back out.

Any water contamination would turn the green paste pink.

 

Regards

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dvderlm

Well I'm slightly wrong about the in-pipe unleaded filler neck sprung flap keeping damp air out. Primary purpose is anti-static, it wipes and connects with nozzle.

 

Secondary purpose is air barrier between that flap and fuel cap.  It's an expansion chamber to avoid people brimming the tank.

Since some fuel tank  caps are vented. To stop fuel coming out around corners with nearly full tank.

It's not an anti-gravity valve for overturned car or anti-syphon protection by design which is achieved with other mechanisms, often plastic.

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dvderlm
23 hours ago, caretakerplus said:

I have no idea if it is still used, but petrol stations used to check their storage tanks for water contamination with a paste, supplied by the oil company.

This green paste was applied to the end of the tank dip stick, the dipstick placed in the tank and immediately pulled back out.

Any water contamination would turn the green paste pink.

 

Like this stuff?

https://www.amazon.co.uk/Water-Finding-Detects-harmful-Heating/dp/B00NU6C036

 

 

That's safer than siphoning out bottom of tank and checking whether small quantity will burn. 

Edited by dvderlm

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