This last weekend Mrs. FBG and I drove across the midwest with our truck to pick up a new tent trailer. That’s a story all in itself, which I won’t go into here. I noticed that all across Nebraska, Iowa and Illinois the “mid-grade” gasoline is about 10 cents/gallon cheapler than the “regular” grade, but it contains 10% ethanol.
What’s the Straight Dope on this stuff. The stickers on the gas pump say that it’s cleaner burning, and I’m sure that the local corn growers are very happy about the situation, but how does ethanol gasolilne impact things like engine life, gas mileage, etc.
Overall my gas mileage for the trip was lower than I normally get, but for the return trip I was towing a 3000 lb. trailer behind me, so I don’t really have any valid data points for comparison.
For you midwest residents who use this stuff, what is your opinion? Good, bad or indifferent?
As a Midwestener with a little knowledge about the ethanol industry, I’d have to say I’m mostly indifferent. But I’m surprised you could find any grade of gasoline that didn’t have ethanol in it.
It does burn cleaner than ordinary gasoline, so there are some environmental benefits at the pump. I don’t want to get into the debate about whether making ethanol is more environmentally harmful because that’s not germane to your experience.
Your gas milage may be a little lower. Not 10% lower, but a little lower.
A 10% ethanol mix won’t do anything to your car. There’s an 85% ethanol mix that requires some modifications to the fuel system, but I’m assuming you didn’t accidentally use that pump.
Seriously, throughout the midwest, at any brand station, I don’t think I’ve seen a non-ethanol gas available for some years now. So, I’d have no valid comparison, but I will say I’ve never heard of or seen any bad effects from using it. Though you’re right, the farm industry is all over this one.
Next up, and a pretty positive development actually is Bio-diesel. Mostly available in blends these days, thoug it can be used straight without engine modifications in heavy diesels. Yeah, it’s a plant based diesel fuel.
When we were living in Ottawa, we had 5%-10% Ethanol fulel available form a fairly big chain that has their own refinning facilities. (Sunnoco) I found about a 10% to 15% decrease in my fuel consumption. The improvements were more pronounced in city driving, less so in highway driving.
When we moved to Calgary, which is a 3,500 ft above sea level, and so where the partial pressure of oxygen is lower, I expected even greater benefits, as ethanol is an oxydiser, which means it contributes oxygen to the combustion reaction. However, I did not see any improvement here in my fuel efficiency compared to name-brand regular unleaded.
Now the only chain that carries here it is an independant chain, (Mohawk) and as far as I know, they don’t do their own refining, but rather buy in bulk from other major oil companies. I mention this because I used to work in a refinery as a summer student, in another city, and it was common practice to have a reserve of gasoline intended four our own branded gas stations, and another stock for the independants and wholesalers. Officially, the reason was that we included special additives in our own stuff that cleaned injectors and prevented gas-line water freeze-ups in the winter, but I know that from time to time, there was a fair bit of junked heavy oil products that were just disolved into the non-branded gas. I would burn ok, but dirtier, less efficiently, and would gum up your injectors eventually. It was a handy way of disposing of the stuff for the company, though, and make it’s own gas perform comparatively better.
So basically, I can’t help but wonder if that’s what’s happening here. Because I can’t see how Ethanol would not have an even more dramatic effect at higher altitude. Any chemists, feel free to educate me.
Living in Illinois myself, most of the stations use 10% ethanol in all grades. The one station that doesn’t, Casey’s, has the situation you describe where mid-grade is cheaper than regular. Most other stations the standard pricing applies.
I avoid the 10% (or higher) stuff: if its put into my parent’s Intrepid, it tends to blow the oxygen sensors and makes the car run badly. Not like crap, but the MPG goes down and it no longer accelrates like it should.
I haven’t had the chance to try it out in my Miata, so I don’t know how that car’ll react to the ethanol. However, the owner’s manual does reccomend that I avoid putting gas with 10% or more ethanol in the tank.
I used to, back in the mid-late '90s when I lived in Houston. Back then, the 10% ethanol blend was labeled as such, and was something like 3 cents a gallon cheaper than the regular kind.
Once they passed the reformulated gas laws, the labeling went away, and I suspect that the gas companies can use whatever oxygen adding compounds they want, so long as the gas meets the specs. So I might be getting 10% ethanol gas, or I might not these days.