The Dreaded Ethanol In Petrol

[bonjo]

hi guys,

after 3 years of working abroad, i am back in the land of wind & rain. Car out of storage and boy am I glad to be driving it with the weather we are having.

I take it that now ethanol is added to all petrols by all suppliers.

Has anyone been monitoring the effect of this undesirable on the fuel consumption?

[crofter]

I understand that about 5% is added to petrol in the UK.

Was'nt this added to lower certain exhaust emissions, not to lower any freezing point?

Good question tho' bonjo

[gjnorthall]

In order to meet various EU directives on renewable energy - petrol companies need to increase the amount of bioethanol (essentially ethanol produced from foodstuff) to a maximum of 5% - most petrol in the UK is now at about this level. It's really all to do with increasing the usage of renewable energy - the secondary issue is that ethanol is a cleaner fuel in emission terms than petrol. However the energy contained per volume of ethanol is only half that of petrol - so the concern is that fuel consumption will increase. There is a plan to increase the addition of bioethanol to a maximum of 10% which is concerning. Some older cars will not run on the 10% fuel. Tests carried out recently by Whatcar indicate no appreciable increase in fuel consumption at the 5% addition but a very significant increase at the 10% level - in general the smaller the engine, the bigger the increase. Whilst bioethanol is a cleaner fuel - the overall increase in fuel consumption at the 10% level will actually increase overall emissions!! Doesn't make much sense against the drive for smaller engined cars and a push to further decrease emissions.

[bonjo]

Yes the whole concept is politician talk.

In fact nobody has yet established the impact of ethanol production on the environment. I hear large amount of the rain forest is burnt down to make space for ethanol producing crops. Of course if this happens in far east Asia, then who cares as long as we meet our emission quotas!

Even farmers producing food have been switching crops as they make more money selling it to refinery than growing rice & potato.

So I can assume 10% mix has not yet been implemented. Thank go for that. In addition to higher fuel costs you mentioned we may have to worry about fuel freshness as ethanol absorbs moisture and over long periods specially in our humid climate there could cause issues with the engine

[Raistlin]

Ethanol is most commonly used to power cars, though it may be used to power other vehicles, such as farm tractors, boats and airplanes.

Ethanol (E100) consumption in an engine is approximately 51% higher than for gasoline since the energy per unit volume of ethanol is 34% lower than for gasoline.

The higher compression ratios in an ethanol-only engine allow for increased power output and better fuel economy than could be obtained with lower compressionratios.

In general, ethanol-only engines are tuned to give slightly better power and torque output than petrol-powered engines. In flexible fuel vehicles, the lowercompression ratio requires tunings that give the same output when using either gasoline or hydrated ethanol. For maximum use of ethanol's benefits, a much higher compression ratio should be used.

Current high compression neat ethanol engine designs are approximately 20 to 30% less fuel efficient than their gasoline-only counterparts.

Ethanol contains soluble and insoluble contaminants.

These soluble contaminants, halide ions such as chloride ions, have a large effect on the corrosivity of alcohol fuels. Halide ions increase corrosion in two ways; they chemically attack passivating oxide films on several metals causing pitting corrosion, and they increase the conductivity of the fuel. Increased electrical conductivity promotes electric, galvanic, and ordinary corrosion in the fuel system.

Soluble contaminants, such as aluminum hydroxide, itself a product of corrosion by halide ions, clog the fuel system over time.

Ethanol is hygroscopic, meaning it will absorb water vapor directly from the atmosphere. Because absorbed water dilutes the fuel value of the ethanol (although it suppresses engine knock) and may cause phase separation of ethanol-gasoline blends, containers of ethanol fuels must be kept tightly sealed.

This high miscibility with water means that ethanol cannot be efficiently shipped through modern pipelines, like liquid hydrocarbons, over long distances.

Mechanics also have seen increased cases of damage to small engines, in particular, the carburetor, attributable to the increased water retention by ethanol in fuel.

[firemac]

In order to meet various EU directives on renewable energy - petrol companies need to increase the amount of bioethanol (essentially ethanol produced from foodstuff) to a maximum of 5% - most petrol in the UK is now at about this level. It's really all to do with increasing the usage of renewable energy - the secondary issue is that ethanol is a cleaner fuel in emission terms than petrol. However the energy contained per volume of ethanol is only half that of petrol - so the concern is that fuel consumption will increase. There is a plan to increase the addition of bioethanol to a maximum of 10% which is concerning. Some older cars will not run on the 10% fuel. Tests carried out recently by Whatcar indicate no appreciable increase in fuel consumption at the 5% addition but a very significant increase at the 10% level - in general the smaller the engine, the bigger the increase. Whilst bioethanol is a cleaner fuel - the overall increase in fuel consumption at the 10% level will actually increase overall emissions!! Doesn't make much sense against the drive for smaller engined cars and a push to further decrease emissions.

Indeed but just imagine all the extra fuel duty & VAT the govt will collect as a result of reduced mpg driving the purchase of extra petrol.

Is it any wonder Cameroon & co haven't objected to the EU's 10% ethanol directive? Barstewards!!

[bonjo]

I did some investigation yesterday, apparently there was quite a bit of new on E10 early February starting with what car ginor mentioned.

the good news is that:

-the government is not currently pushing for E10 to be introduced and is leaving it up to the suppliers

-changes have to be made to the pumps and suppliers are not currently keen to spend the money.

-if E10 is introduced, it will be only for regular unleaded and the pumps have to be labelled. the super unleaded will remain at E5 (off course costs more)

-the drop in fuel consumption and increase in CO2 is worse for smaller engine cars

- in mainland Europe apparently things are happening at a slower paste (lucky devils)

- if the renewable energy quota is achieved with existing E5 and bio diesel and hybrid cars, then E10 may never show it's head

having gone through the leaded petrol withdrawal trauma, i hope this one will not be as bad!