Consequences of Mixing Alcohol and Gasoline?

[HarleyLee]

Alcohol and gasoline can be mixed. Alcohol can dissolve gasoline. Alcohol molecules consist of a hydroxyl group connected to an ethyl group. The ethyl group is an oil-loving (lipophilic) group, while the hydroxyl group is a water-loving (hydrophilic) group, which is why alcohol can dissolve gasoline. Below are some relevant details: Gasoline is composed of over 99% carbon and hydrogen, along with some aliphatic and naphthenic hydrocarbons. When exposed to air, it can produce some gummy substances. Theoretically, gasoline hardly deteriorates if air is completely excluded. Modern gasoline contains antioxidants, and conservatively, it can be stored for about 8 months. Some regions now use ethanol gasoline, which is a blend of 90% regular gasoline and 10% fuel ethanol. Due to the 10% ethanol content, ethanol gasoline has a shorter shelf life, lasting up to one month at most. Comparing vehicles from regions that consistently use ethanol gasoline with those from regions that alternately use pure gasoline and ethanol gasoline, there are noticeable differences in fault phenomena and distribution of fault locations. Alternating use can easily lead to fuel leakage and exceedance of emission standards. It also increases the likelihood of engine component and EGR system failures, while other aspects show no significant differences. However, vehicles that alternate between pure gasoline and ethanol gasoline exhibit fewer lubrication system and three-way catalytic converter faults compared to those that use ethanol gasoline exclusively.

[VonGage]

I have dealt with many cases of problems caused by alcohol-blended gasoline. The most common consequence is corrosion of engine components, especially rubber and plastic parts that rapidly deteriorate and develop oil leaks. For example, when pure alcohol is added to a regular fuel tank, it dissolves deposits inside the tank, leading to clogged fuel injectors, which can cause cold-start difficulties or sluggish acceleration. Additionally, if the mixing ratio is incorrect, such as adding high-concentration alcohol, the risk of water separation increases, with condensation forming water droplets that affect combustion efficiency or even cause stalling. Long-term use can also damage oxygen sensors and cause exhaust pipes to rust, potentially leading to a complete overhaul of the fuel system. I advise vehicle owners to strictly follow the vehicle manual and use the specified fuel, avoiding self-mixing to save small amounts of money only to spend large sums on repairs later.

[LeJoshua]

I think adding alcohol like ethanol to gasoline has both advantages and disadvantages. From an environmental perspective, it can reduce carbon emissions and dependence on petroleum, with formulations like E10 being quite popular. In actual driving, it increases the octane number, allowing the engine to burn cleaner, but the drawbacks are obvious. Alcohol has strong hygroscopic properties, leading to water accumulation in the fuel tank, especially in cold weather when it can solidify and freeze, making it difficult to start the car. Fuel consumption increases because alcohol has a lower energy density, requiring more fuel to travel the same distance. Compatibility issues are also important, as non-flexible engine materials, such as those in older cars, can corrode seals, leading to oil leaks. Overall, this blend is suitable for modern designed cars, but older vehicles should avoid it to prevent unexpected breakdowns affecting travel.

[KennedyLee]

As someone who has driven for years, I've used ethanol-blended gasoline with decent experience. Initially, it did save some fuel costs. However, occasionally with improper mixing or purchasing low-quality products, the engine would feel weak with slow acceleration, and once even failed a cold start. A friend recklessly mixed in high-alcohol-content liquid, causing severe vehicle shaking that required repairs. The consequences usually involve component corrosion affecting performance, so I advise against risking mixing other alcohols—just opt for regular E10-type fuel at gas stations for peace of mind.