Ethanol?
05-24-2006, 07:29 PM
#3
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What kind of problems are you having?
You could be experiencing problems due to water in your fuel. Water normally remains separated from gas but it will mix with ethanol and both the ethanol and water will separate from the gas. If this makes its way to the motor it will run rough.
The water could have been in your gas tank (condensation buildup) or it could have been in the gas station tanks. When stations make the switch to ethanol the tanks are supposed to be purged and cleaned before they put E10 in them. If that was not done or done improperly some water could have remained in the tank and mixed with the E10.
Another problem could be the ethanol/water mixture picked up contaminants in your tank and transported them to the fuel filter and cloggged it.
Unless you are having significant problems I'd first switch gasoline stations and brands for a while and see if that cures the probelm. If not, try replacing the fuel filter. If the problem is bad or minor drivabililty problems continue, get it checked. If it is due to water in your tank that you can trace to a gas station, the station or the oil company may reimburse you for any repairs.
The water could have been in your gas tank (condensation buildup) or it could have been in the gas station tanks. When stations make the switch to ethanol the tanks are supposed to be purged and cleaned before they put E10 in them. If that was not done or done improperly some water could have remained in the tank and mixed with the E10.
Another problem could be the ethanol/water mixture picked up contaminants in your tank and transported them to the fuel filter and cloggged it.
Unless you are having significant problems I'd first switch gasoline stations and brands for a while and see if that cures the probelm. If not, try replacing the fuel filter. If the problem is bad or minor drivabililty problems continue, get it checked. If it is due to water in your tank that you can trace to a gas station, the station or the oil company may reimburse you for any repairs.
05-24-2006, 09:53 PM
#4
There should be no serious issues.
As FtW said, there could be issues due to the change in fuel. This should work itself out. Change your filter, try a different gas station, etc.
05-25-2006, 02:50 AM
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Problems..
I've noticed a bit of a lag to fire up when starting the car in the morning and it SEEMS as if the fuel mileage sucks when the engine is cold; when the engine if fully warmed it feels and runs fine.
It could be unrelated, or a figment of my imagination, but I noticed that I filled the tank with the 10% Ethanol fuel and now the engine cranks a bit more than usual (or at least as memory serves).
It could be unrelated, or a figment of my imagination, but I noticed that I filled the tank with the 10% Ethanol fuel and now the engine cranks a bit more than usual (or at least as memory serves).
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05-25-2006, 06:51 AM
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Here is the official BMW stand on it (explains a lot)
They've done a credible job explaining all this so just read below if you're interested. Although it's a BMW bulletin, it would apply to Audi with the exception of warranty info.
Subject-Alcohol Fuel Blends in BMW Vehicles
All with gasoline engines
Fuel blends containing a high percentage (above 10%) of alcohol, mainly ethanol, are becoming more commercially available. Customers inquire about the possibility of using alcohol fuels (e.g. E85) in BMW vehicles
INFORMATION
Fuels containing up to and including 10% of ethanol or other oxygenates with up to 2.8% oxygen by weight, that is, 15% MTBE (methyl tertiary butyl ether) or 3% methanol plus an equivalent amount of co-solvent, will not void the applicable warranties with respect to defects in materials or workmanship.
Although, usage of such alcohol fuel blends may result in drivability, starting, and stalling problems due to reduced volatility and lower energy content of the fuel. Those drivability problems may be especially evident under certain environmental conditions, such as: high or low ambient temperatures and high altitude.
Only specially adapted vehicles (FFV - Flexible Fuel Vehicles) can run on high alcohol fuel blends.
BMW, for the various technical and environmental reasons explained below, does not offer FFV models.
Usage of E85, or any other high alcohol content blend (e.g. E30) in BMW vehicles, will cause various drivability complaints (cold start problems, stalling, reduced performance, poor fuel economy, etc.), may cause excessive emissions, and may cause irreversible damage to engine, emission control and fuel delivery systems due to incompatibility of materials with alcohols.
General Notes Regarding E85 Fuel.
E85 fuel contains 85% (by volume) of ethanol and 15% of gasoline. Ethanol can be produced chemically from ethylene or biologically from grains, agricultural wastes, or any organic material containing starch or sugar. In the US, ethanol is mainly produced from corn and is classified as a renewable fuel.
Similar to gasoline, ethanol contains hydrogen and carbon; with additional oxygen molecules build into its chemical chain. This chemical structure makes ethanol***8217;s burning process slightly cleaner compared to the gasoline (lower tailpipe emissions).
On the other hand, due to lower carbon content, ethanol provides 27% less energy (for identical volume) then gasoline, resulting in the reduced fuel economy of E85 vehicles (approximately 22% higher consumption). Increased fuel consumption requires the appropriately enlarged fuel tank capacities (usually 30% increase), and the specific DME calibrations for the E85 lower Stoichiometric air/fuel ratio (10 compared to 14.7 for gasoline engines).
E85 fuel volatility is typically lower then gasoline (RVP 6-10 psi, compared to 8-15 psi for gasoline). Lower fuel volatility will reduce vehicle evaporative emissions, but it may cause cold starting problems especially with lower ambient temperatures.
Under certain environmental conditions, mainly lower ambient temperatures, ethanol separates from gasoline/alcohol mixture and absorbs water. The ethanol absorbed water molecules are heavier then gasoline or ethanol, they remain at the bottom of fuel tank and when introduced into combustion process they tend to form an extremely lean mixture resulting in misfire, rough idle and cold starting problems.
Certain materials, commonly used with gasoline are totally incompatible with alcohols. When these materials come in contact with ethanol, they may dissolve in the fuel, which may damage engine components and may result in poor vehicle drivability.
Some metals (e.g. zinc, brass, lead, aluminum) become degraded by long exposure to ethanol fuel blends. Also, some nonmetallic materials used in automotive industry such as: natural rubber, polyurethane, cork gasket material, leather, polyvinyl chloride (PVC), polyamides, methyl-methacrylate plastics, and certain thermo & thermoset plastics degrade when in contact with fuel ethanol.
In order to safely and effectively operate a motor vehicle running on E85, the vehicle must be compatible with alcohol use. Some manufacturers have developed vehicles called FFV (Flexible Fuel Vehicle) that can operate on any blend of ethanol and gasoline (from 0% ethanol and 100% gasoline, up to 85% ethanol and 15% gasoline). Ethanol FFVs are similar to gasoline vehicles, with main differences in materials used in fuel management and delivery systems, and DME control module calibrations. In some cases, also E85 vehicles require special lubricating oils.
Aftermarket conversions of gasoline-powered vehicles to ethanol-fueled vehicles, although possible, are not recommended due to internal materials and DME software incompatibility, as well, as the high costs of conversion.
WARRANTY INFORMATION
Components damage/malfunctions, or any drivability problems caused by use of fuels containing more then 10% ethanol (or other oxygenates with more then 2.8% oxygen by weight) will not be covered under BMW warranties with respect to defects in materials or workmanship.
Subject-Alcohol Fuel Blends in BMW Vehicles
All with gasoline engines
Fuel blends containing a high percentage (above 10%) of alcohol, mainly ethanol, are becoming more commercially available. Customers inquire about the possibility of using alcohol fuels (e.g. E85) in BMW vehicles
INFORMATION
Fuels containing up to and including 10% of ethanol or other oxygenates with up to 2.8% oxygen by weight, that is, 15% MTBE (methyl tertiary butyl ether) or 3% methanol plus an equivalent amount of co-solvent, will not void the applicable warranties with respect to defects in materials or workmanship.
Although, usage of such alcohol fuel blends may result in drivability, starting, and stalling problems due to reduced volatility and lower energy content of the fuel. Those drivability problems may be especially evident under certain environmental conditions, such as: high or low ambient temperatures and high altitude.
Only specially adapted vehicles (FFV - Flexible Fuel Vehicles) can run on high alcohol fuel blends.
BMW, for the various technical and environmental reasons explained below, does not offer FFV models.
Usage of E85, or any other high alcohol content blend (e.g. E30) in BMW vehicles, will cause various drivability complaints (cold start problems, stalling, reduced performance, poor fuel economy, etc.), may cause excessive emissions, and may cause irreversible damage to engine, emission control and fuel delivery systems due to incompatibility of materials with alcohols.
General Notes Regarding E85 Fuel.
E85 fuel contains 85% (by volume) of ethanol and 15% of gasoline. Ethanol can be produced chemically from ethylene or biologically from grains, agricultural wastes, or any organic material containing starch or sugar. In the US, ethanol is mainly produced from corn and is classified as a renewable fuel.
Similar to gasoline, ethanol contains hydrogen and carbon; with additional oxygen molecules build into its chemical chain. This chemical structure makes ethanol***8217;s burning process slightly cleaner compared to the gasoline (lower tailpipe emissions).
On the other hand, due to lower carbon content, ethanol provides 27% less energy (for identical volume) then gasoline, resulting in the reduced fuel economy of E85 vehicles (approximately 22% higher consumption). Increased fuel consumption requires the appropriately enlarged fuel tank capacities (usually 30% increase), and the specific DME calibrations for the E85 lower Stoichiometric air/fuel ratio (10 compared to 14.7 for gasoline engines).
E85 fuel volatility is typically lower then gasoline (RVP 6-10 psi, compared to 8-15 psi for gasoline). Lower fuel volatility will reduce vehicle evaporative emissions, but it may cause cold starting problems especially with lower ambient temperatures.
Under certain environmental conditions, mainly lower ambient temperatures, ethanol separates from gasoline/alcohol mixture and absorbs water. The ethanol absorbed water molecules are heavier then gasoline or ethanol, they remain at the bottom of fuel tank and when introduced into combustion process they tend to form an extremely lean mixture resulting in misfire, rough idle and cold starting problems.
Certain materials, commonly used with gasoline are totally incompatible with alcohols. When these materials come in contact with ethanol, they may dissolve in the fuel, which may damage engine components and may result in poor vehicle drivability.
Some metals (e.g. zinc, brass, lead, aluminum) become degraded by long exposure to ethanol fuel blends. Also, some nonmetallic materials used in automotive industry such as: natural rubber, polyurethane, cork gasket material, leather, polyvinyl chloride (PVC), polyamides, methyl-methacrylate plastics, and certain thermo & thermoset plastics degrade when in contact with fuel ethanol.
In order to safely and effectively operate a motor vehicle running on E85, the vehicle must be compatible with alcohol use. Some manufacturers have developed vehicles called FFV (Flexible Fuel Vehicle) that can operate on any blend of ethanol and gasoline (from 0% ethanol and 100% gasoline, up to 85% ethanol and 15% gasoline). Ethanol FFVs are similar to gasoline vehicles, with main differences in materials used in fuel management and delivery systems, and DME control module calibrations. In some cases, also E85 vehicles require special lubricating oils.
Aftermarket conversions of gasoline-powered vehicles to ethanol-fueled vehicles, although possible, are not recommended due to internal materials and DME software incompatibility, as well, as the high costs of conversion.
WARRANTY INFORMATION
Components damage/malfunctions, or any drivability problems caused by use of fuels containing more then 10% ethanol (or other oxygenates with more then 2.8% oxygen by weight) will not be covered under BMW warranties with respect to defects in materials or workmanship.
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