Generally ethanol is not harmful to the engines, especially in this low percentange.
(The pure) Ethanol has greater octane number opposed to petrol (105 vs 95..98),
when added to regular petrol the octane number will be increased.
In many european countries the regular 95 petrol contains 5-8% ethanol too.
My 33 is often running on 20-40% ethanol-petrol mixture.
Advantages of ethanol:
- Cleaner, smut-free burn
- Increased life of the oxygen sensor and catalytic converter
- Lower the harmful emissions (even up to 60 percent)
- Because of the higher octane number it can eleminate the detonation,
the engine can run with increased ignition advance (better torque) and/or
raised compression ratio (like mine)
- Keeps the fuel system clean
- Will be available when the fossil fuels are gone forever
Disadvantages of Ethanol:
- Lower energy content, this is important when the fuel contains more than 20% ethanol.
Because of the lower energy content the engine needs more fuel to maintain the power,
that's why the carburettor needs to be re-jetted to avoid lean running. Vehicles with closed-loop
control injection can automatically adapt to ethanol when it's percentange under 50% in the fuel.
- The fuel consumption will increase (when the ethanol percentange is over 15% in the fuel)
- Ethanol is hygroscopic. The fuel system should be water-free. (important mainly at older vehicles)
- Ethanol is able to solve smudge in the fuel system which is unharmed by the petrol. So if higher
percentanges of ethanol is used in the fuel the fuel filter should be replaced after the first 500km.
- Ethanol has slight corrosive effect on copper parts (important only when the percentange is over
40% in the fuel)
- Below 10 degree Celsius increased enrichment needed when starting the cold engine (above 30-40% in the fuel)
Last edited by LoneWolf33; 28-01-11 at 13:09.