Ethanol damaging to internal combustion engines?


in Politics, The environment

Reflection in a chandelier

The many problems with ethanol as a fuel have been mentioned here before: the climate and energy security benefits are dubious on a life cycle basis, making it from food crops harms the poor, the economics of cellulosic ethanol remain unknown, it has less energy content than gasoline, it is corrosive, it mixes with water, etc. For these reasons and others, most informed environmentalists completely reject corn-based ethanol as a climate change solution, though many remain hopeful that better feedstocks will be found. Ed Wallace raises yet another objection to its use in motor vehicles, namely that it can damage their engines.

Apparently, gasoline with more than 15% ethanol blended in can damage plastic fuel intakes, corrode surfaces even within special ethanol-tolerant ‘flex fuel’ vehicles, and can attract moisture in a way that can generate acids during storage. I don’t know enough about motor vehicle engines to comment personally, but perhaps some readers will be able to assess the probable severity of these issues.

None of this is to say that ethanol certainly has no role whatsoever in our future mix of transportation fuels. Rather, it suggests that the shift may not be as trouble-free as ethanol’s most enthusiastic promoters suggest. For a whole slate of reasons, the idea that we can easily move from fossil fuel dependence to reliance on domestic crops and ethanol-fuelled vehicles is a falsehood. The process of overcoming fossil fuel dependence will require both more intelligent lifecycle considerations of the total impacts of fuel production and, probably, a greater willingness to alter our overall transportation infrastructure.

Personally, I think hydrogen is a pipe dream and ethanol and biodiesel may find niche roles, but electric vehicles are likely to become the dominant form of ground transport over short-to-moderate distances.

{ 6 comments… read them below or add one }

Matt July 9, 2009 at 1:01 pm

The problem of ethanol fuels damaging regular engines is one I read about years ago, but it surprises me to read that maybe they can damage flex fuel vehicles (although I’d want to see a study or something other than a automotive reporter’s opinion).

I like to run Mohawk gasoline (up to 10% ethanol) in my car, because my car is designed for 91 Octane gas, but I find it runs just fine on Mohawk’s 90 Octane gas, which costs the same as any other gas station’s 87 octane. I notice a lot of new Chrysler and GM vehicles proudly sporting E85 Flex Fuel badges, but I find this completely silly, because I’ve never seen it for sale! I have no idea where you’d go to buy it even if you wanted to use it. I really feel as though it’s total green-washing to the point where there’s zero difference between their cars and a non flex-fuel vehicle. In fact, I mostly see the badge on their SUVs and Trucks which to me is a bit of irony, because those are their least green vehicles.

One of the other issues with running E85 in your car (if you could buy it) besides corrosion, is that the energy density of E85 is significantly less than regular gasoline, and your MPGs drop a lot using it. Assuming it cost the same as regular gas, it would be burdensome to pay a premium to use it.

coyote July 9, 2009 at 3:37 pm

Back when alcohol first came up as a fuel alternative, back in the tetraethyl lead days, it was considered to be somewhat harder than gasoline on stock valve stems and seats. It also perished the stock rubber hoses used to plumb vehicles at the time. And it was suspected of dissolving and re-suspending varnish and other residues deposited on interior bits of engines and fuel systems, and from there carrying extra crud into combustion chambers to accelerate deposits on spark plugs, valves and whatnot over the short term. At least until the engine and plumbing cleaned itself out with repeated fuelings.

When lead was removed from gasoline, valve seats were hardened up at the factories, supposedly solving that problem. And the claim was that in small percentages, alcohol couldn’t corrode newer synthetic hoses and plastic fittings.

Given that we often find that plastics in all sorts of applications are nowhere near as inert as their proponents initially thought (hello, BPA water and food containers…) and that flex-fuel technology was sorta rushed to market, Ed Wallace’s knock (heh) against ethanol is at least plausible.

But I rather think the lifecycle arguments against its use to be of greater concern. Internal combustion motors inherently start knocking themselves to pieces in a dozen different ways, from the first time they’re fired up. Alcohol may accelerate this a bit, but the trend is already there. My two cents worth, for what it’s worth.

Tristan July 10, 2009 at 10:27 pm

Currently I’m driving a 1991 vehicle across Canada and it seems everywhere I fill up the gasoline may have up to 10% ethanol. I suppose I’m the monkey in this experiment – if my car breaks, I’ll write here about it.

Incidentally, I saw a sign today saying “scrap that old beater (95 or older)”. My car may not be in perfect condition, but it has a distributorless ignition, multiport fuel injection, O2 sensor, mass airflow meter. Basically, no less advanced than a modern car. We live in strange times when such an advanced piece of technology is considered a “beater”.

Matt July 10, 2009 at 11:03 pm

I’m in the same boat as you in terms of the age, but relative high value of my car. I’d like to point out some technologies that our cars wouldn’t benefit from, though, and which you’re no doubt aware of: Variable valve timing, electronic (drive-by-wire) throttle, and in some cases direct injection and electric power steering. Combined, those technologies do sort of make cars our age ‘old technology,’ even if our cars still perform well.

Modern cars are quite heavy, so the efficiency gains of these technologies are usually offset by the extra mass, but that’s sort of an aside to the point.

Tristan July 11, 2009 at 11:21 am

I’m unconvinced by drive-by-wire throttles, but agree with every other aspect of your point. In my car, my foot is literally connected to a piece of metal touching the engine – so, if the engine isn’t running smoothly I know it immediately. I find driving cars with drive by wire throttles to feel disconnected and remove. I drove a new Taurus (rental) and I found it difficult to maintain a steady speed without using the cruise control because of the dead feeling throttle.

What is the advantage of a drive by wire throttle? This car has electronic computer controlled cruise control – so it has a linkage to connect the computer to the throttle, what could be the advantage of making the throttle itself computer controlled?

The cars I’ve driven with electric power steering also seem to have worse steering than the old rack and pinion power assist set up, but then again BMW probably has an electric power steering system that is brilliant. Actually, whatever my complaints are, BMW probably has a way around them, simply because they sell specifically to customers that value driver involvement.

Tristan July 11, 2009 at 11:23 am

Incidentally, this kind of acts as proof that things are “getting better”. When my dad was younger he bought a 62 Jaguar when it was 18 years old – the same age as this car now. While the Jag certainly has it over the Previa in coolness, the Jag needed everything fixing constantly whereas this car seems to “just work”.

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