Flexible-fuel (flex-fuel) vehicles – How do they work? – rpmGo.com



Last week, we heard about Bentley fitting its flexible-fuel 6.0-liter W12 engine to all of its Continental range. But while many of us figure out that this means the car will run on gasoline, E85 ethanol fuel or any mixture of the two, not a lot of people know the full deal behind these flex-fuel vehicles.

That’s why we decided to tackle this technology. Whether it’s called flexible-fuel, flexi-fuel, flex-fuel, flexifuel or anything in between, we’ll present the advantages, disadvantages and why we might see it implemented in more and more vehicles.

Curious to find all that out? Hit the jump!

Flexible-fuel vehicles (FFVs) can run on gasoline, ethanol E85 or any mixture of the two substances. Research is being done to combine methanol and other fuels, but the most common example is the one highlighted above.

Such cars, buses or lightweight trucks have quite a few advantages. First off, the CO2 emissions are much lower, sometimes by 70%, meaning the carbon footprint of the vehicle is drastically reduced. The fact that E85 ethanol is mostly obtained from sugar cane means that it is a renewable energy source, unlike the old fossil fuels.

Because E85 is much safer for the environment, many governments, with Brazil leading the pack, subsidize the cost of production, meaning a lower price at the filling station. So while you may pay extra for an FFV, it will balance out over time. If an oil crisis rears its ugly head, like a few years ago, you’ll be pretty safe from its effects.

Another added bonus is that while you can fill up with E85 from quite a few stations, you can still opt to fill up with regular gasoline, in case the closest ethanol station is further than the current range of the car. The ethanol infrastructure is pretty developed in quite a few countries, like Brazil, USA or Sweden, and is quickly expanding in other territories.

Sadly, there are still some disadvantages to using FFVs. First off, ethanol, like the hydrogen fuel cell we talked about a few weeks ago, can’t perform very well in cold conditions. As such, it is advised to either switch to E70/E75 mixture, which adds more gasoline to the mix, or just fill up with more gasoline, instead of E85, during the winter.

Besides the cold weather problems, FFVs aren’t that efficient, consuming more fuel than regular gasoline cars. Even though they don’t emit as much CO2 as conventional vehicles, FFVs actually put out more smog. In crowded cities like Los Angeles or Beijing, such a thing only worsens the living conditions.

Overall, flexible-fuel vehicles are gaining ground in various territories. Even though they aren’t the most efficient types of cars out there, they still have quite a few more traits than regular, fossil fuel-powered vehicles. More and more carmakers are offering flex-fuel variants of their models, so the choice range is expanding.

This has been a part of our RPMGO Answers feature, which tackles various automotive debates or questions, and tries to find a simple explanation or to reveal all sides of the discussion.

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Post tags: Tags: flex-fuel, flexible fuel vehicles, RPMGO Answers