Vaagen skrev:Det er vel slik at etanol øker oktan-tallet, ikke reduserer det? Det var vel det som gjorde at SAAB kunne ha en flexifuel-motor som ga 180 hk med etanol og 150 med bensin.
Det er rett at etanol øker forbruket, det er fordi energiinnholdet er lavere. Likedan er det vel rett at for mye etanol kan ødelegge ymse gummi- og plastdetaljer. SAAB'ene jeg nevnte hadde andre bensintanker og -ledninger enn de som var beregnet for ren bensin.
Som noen andre sa, det som selges er nok helt trygt og 5 % innblanding er helt sikkert OK i forhold til bensinledninger osv. At det innblandingen øker forbruket litt (1 % kanskje?) er vel ikke oljeselskapene lei seg for...
Etanol er ikke bra i drivstoff, selv med 5 %. Mange motorer tar skade med så lite som 5 % etanol i drivstoff. Likevel bør man ikke bli forbauset om mengden
etanol i drivstoff øker. Det har vært, og er, tendensen. Feks heter det (
http://www.frost.co.uk/protect-your-veh ... st-ethanol" onclick="window.open(this.href);return false; ) :
Protect Your Vehicle Against Harmful Impact of Ethanol Blended Petrol
If you use petrol for your family car, classic car, boat, motorcycle, Quad, lawnmower, strimmer, rotavator, chainsaw, generator, pump or any other type of equipment that has a petrol engine, you need to know about Ethanol in your fuel.
What is Ethanol?
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colourless liquid. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a solvent and as an alcohol fuel. In common usage, it is often referred to simply as alcohol or spirits.
Where does it come from?
Ethanol is sustainable and domestically produced from renewable resources such as corn, grains and potatoes.
Why add Ethanol to Petrol?
Ethanol is good for our agricultural economy and helps us reduce our dependency on foreign petroleum products. On the “green” side they are aimed at improving air quality and reducing air pollution from fuel emissions.
What proportion of the fuel is Ethanol?
Permitted ethanol content in petrol is 5% which is to rise to 10% in 2013. However we are led to believe supermarket fuels may already have as much as 10% ethanol blended in. We hear a 15% mix is on its way in the USA.
While this is good for the domestic farmer and our environment, Ethanol can cause serious problems to your engine and fuel system. Generally vehicles built after 1996 have been designed with Biofuels in mind, but earlier cars and engines with carburettors are going to need help. What types of problems have been encountered?
1) Water accumulation in the fuel tank - ethanol absorbs water from the air. The water condenses in the fuel tank and will pull the ethanol out of suspension with the petrol. This is bad news because it strips the octane out of the petrol, leaving you with a layer of octane-poor fuel on top and a water-ethanol layer mixture on the bottom. If this gets sucked into the combustion chamber, you will have poor starting and very rough running with potentially engine damage.
2) Deposit is like to build up - Ethanol when mixed with water readily forms Gums in the fuel system much quicker than fuel without Ethanol. These Gums coat fuel system components including filters, carburettors, injectors, throttle plates and will then form varnish and carbon deposits in the intake, on valves, and in the combustion chamber.
3) Lower fuel mileage, Decreased performance and acceleration. Ethanol contains less chemical energy than petrol does, and this means less mileage for the driver. 3-5% drops in mileage are expected.
4) Corrosion of internal engine components - Water contamination may cause fuel system corrosion and severe deterioration.
5) Contaminants in fuel system – water, degraded rubber, plastic, fibreglass and rust may get drawn in.
6) It could encourage microbial growth in fuel. Ethanol being organic and hygroscopic may allow the growth of fungus.
7) Short shelf life - as short as 90 days

Corrodes plastic and rubber - Ethanol is a strong, aggressive solvent and will cause problems with rubber hoses, o-rings, seals, and gaskets. These problems are worse during extended storage when significant deterioration could take place. Hoses may delaminate, o-rings soften and break down, and fuel system components made from certain types of plastics could either soften or become hard and brittle, eventually failing. Fuel system components made from brass, copper, and aluminium may oxidize. The dissolved plastics and resins now in the fuel could end up in blocked fuel filters or gummy deposits.
9) Melts Fibreglass - bikes and boats with fibreglass fuel tanks can have structural failure as the Ethanol will break down and pick-up some of the materials the tanks are made from. Again this material, dissolved from the tank, can be carried through the fuel system and can cause damage to carburettors, fuel injectors and can actually get into the combustion chambers.
Selv "litt" etanol i bensin kan ha ulemper for forbrukeren. Jo mer etanol i drivstoff, desto verre, for mange motorer.
Mitsubishi's GDI-motorer feks, har ikke godt av bensin med etanol, og 98 oktan ble på et tidspunkt anbefalt, fordi 98 oktan (i alle fall på det
tidspunktet) ikke inneholdt etanol(
http://www.vibilagare.se/test/begbil/be ... agon-12419" onclick="window.open(this.href);return false; ):
"...Det vanligaste felet på Space Wagon gäller ryckig motorgång. Motorn har nämligen problem med att den sotar igen. Sotavlagringar bildas och sätter igen spjällhuset, ett fel som drabbar nästan alla bilar med Mitsubishis olika GDI-motorer. Då krävs en rengöring av spjällhuset. Men vanligare är att motorns insug måste blästras med en speciell teknik.
Mitsubishi har ett förlängt goodwillåtagande för just igensotade GDI-motorer. Det gäller 72 månader eller 15 000 mil. Men då måste bilarna vara servade på auktoriserade verkstäder, annars får ägaren själv stå för kostnaderna, som kan hamna på 5 000 till 6 000 kr. Boven anses vara bensin med inblandning av etanol och verkstäderna rekommenderar att köra bilen på 98 oktan - om den inte innehåller etanol. Det fördyrar driften.
..."
Det er naturligvis de som hevder at etanol i drivstoff er "ufarlig". Produsenter av sigaretter har også hevdet at sigarettrøyking er ufarlig..
Heldigvis er det ikke direkte helseskadelig med etanol i drivstoff (såvidt jeg vet). Vi får som forbrukere økte verkstedregninger. Dette i sin tur
øker omsetningen hos verksteder og deleprodusenter, som i sin tur kan stimulere økonomien.
Ikke sikkert det er så dumt, i et større perspektiv, men de av oss som har eldre kjøretøy spesielt, får merke det på pengepungen.