Modern fuels damaging rubber components?

John Targett at a Goodwood Track Day (Photo: Victor Smith)

John Targett, an English auto plastics specialist and V8 enthusiast in the US, has sent in a contribution to the debate started by Barrie Jones. (Jan 08)

There is a major mis-statement in Barrie's summary in his briefing note in that even my '04 GMC Yukon is rated to run on E85, as have most of GM's fleet for some years. Yes E85 is 85% ethanol and E10 is 10% ethanol . . . truly! Not yet commonly available in the US, but evidently on it's way. The farmers, and converters of corn to ethanol, are beginning to catch up with production of ethanol such that E85, which has been

largely unavailable, is now appearing at a few petrol stations. Those who have tried this in an effort to be "green" and patriotic find that the cost is higher than regular E5 or E10, and their vehicles' fuel consumption collapses by at least 20% and up to 25%! Reeling from the price of gasoline doubling during the past couple of years, drivers' enthusiasm for use of E85 is hard to find.

Meanwhile, the addition of ethanol at 10% is indeed quite widespread, such that fuel consumption in winter time (in the colder parts of this large country) is noticeably worse, as Barrie notes in his observation about more difficult starting. I am puzzled that, since ethanol contains additional O2, use of it adversely affects fuel economy; will have to think about that one. It must contain less energy per given volume.

Meanwhile, I will think too about the possible effect of ethanol on plastics that will have been selected for use in petrol. My first reaction is that there may not be a problem, since petrol immersion itself is a tough environment. Rubber is a different animal, and I can certainly picture that ethanol may leach out some of the additive packages and cause embrittlement. Manufacturers here of course have produced rubber formulations rated for use with E85 even, to keep GM and several other manufacturers happy. I imagine that such tubing is available in Britain and mainland Europe. It's a good subject to attract readers to the V8 website!

Posted: 25.1.08

See also the earlier useful briefing note from Barrie Jones and reports of known problems.

Wisdom of the rush to biofuels?
John Targett prefaced his comments above on the ethanol damage to rubber components with a brief digression on the wisdom of the rush to biofuels saying it would be interesting indeed to have a discussion on this topic, central Government interference in the market place, and the law of unintended consequences!

John comments: briefly, the Feds here decided it would be popular to "reduce dependence on imported oil" so have subsidised farmers who grew corn for conversion to ethanol. The subsidy was generous, so especially the big farms switched to growing corn. Guess what happened? Cattle are fed corn which becomes scarce now it's being shipped to ethanol producers, so corn feed doubles in price. The cost of beef and milk escalates wildly. Farmers like the subsidy so much that they now convert their fields that produced other crops and vegetables to growing even more corn; price of bread doubles and vegetables (very healthy to eat one's veggies) prices rocket! You can picture the reaction! "I'm from the Government, and I'm here to help". Sure.


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