dmill89

The funny thing is that ethanol isn't even good for the environment, and most "environmentalists" don't even support it any more, the only thing keeping ethanol alive is the corn lobby and their sizable "campaign contributions".

mr white

Which means it's higher octane than straight gasoline. Not a big deal in the Cherokee, but in vehicles with higher compression or forced induction it is necessary to prevent detonation.

jedijeb

E10 and E85 are better in higher compression engines, but just having a lower BTU/gal is not directly related to Octane rating, which is the fuel's ability to resist detonation. Ethanol and Liquidified Natural Gas have nearly identical BTU/gal ratings, but Ethanol has an Octane rating of 110 and LNG has an octane rating of 120. Also Methanol has nearly 30% less BTU/gal but has an octane rating of 112 which is better than Ethanol. The Octane rating for Diesel#2 is 15, while it's BTU/gal is only about 15% higher than Gasoline.

There is only a vague relation between octane rating and BTU/gal of a fuel. I have seen people actually mix a little diesel fuel with gasoline to improve the octane rating which would seem impossible since the rating for diesel is so low. If you ever had to use Chainsaw gas to make it home from the woods you will know how it works, it may smoke like crazy but your engine will not knock at all. (Don't try that with newer vehicles with catalytic converters, it is not good for them)

mr white

I wasn't saying it has higher octane because of less energy per unit. The guy I quoted said it is harder to ignite which I was elaborating on. I should have specified.

s346k

i got an avg of 18.1 mpg during a week of sub 0 temps. I used 4wd twice totaling about 30 miles and had roughly 3 hours of idle time that week. cold weather definitely affects mileage, but I think less of it is related to the ethanol content in the fuel and more of it is because we drive slower, it takes longer to warm an engine (and everything else mechanical holding oil etc) to operating ie most efficient temps.


e85 is a great example of don't hate the player, hate the game.


the only negatives it has as a fuel directly related to its use is fuel economy. looking at it from an enthusiast's point of view - it's awesome. I can now buy 100+ octane fuel out of the pump for less than 87 octane. my vehicle is now capable of making more power and burning MUCH MUCH cleaner. any of you ***** ever seen the combustion chamber/exhaust of a properly tuned e85 car? the spark plugs literally look new for thousands of miles, as does every part between the face of the valve to the tip of the exhaust. it is one of the best cleaners for fuel tanks and fuel lines on the planet. that's why it "clogs carbs". it is cleaning the built up gunk out of your fuel system.

peep

Colder winter, more warm up time, more storms, more snow, way more 4x4 running. Less mileage. And of course the dang gas costs more.

gbalili74

My 3 88/89 Xj's was doing about 430 to 380 miles on a full tank. Now when i drive each of them, now there getting 250 to 318. Per full tank. And there's nothing wrong with each of them. It has to be the gas!!!

salad

Has it occurred to anyone that maybe thicker fluids have some involvement... You know that gear oil is kinda thick below freezing. Oh and maybe it takes longer for the rings to completely seal when the pistons have cooled down to -10. And maybe the cold intake air temp tells the computer to dump more fuel in to meet the correct stochiometric A/F ratio on account of the denser air.

No... That can't have anything to do with it...

This thread cracks me up lol

black label

Post #26 I believe.

jedijeb

I took those things into account also and they do have an affect. The last few tanks of gas though were run under nearly the same weather conditions. Mornings were about 40-45F days were about 60F mixture of drizzly rain or sunny days, all about a week per tank of fuel. My best mileage was actually on one of the cooler weeks. I had relatively little difference from when the temps were near 0F and when they were holding in the 50F range.

There was however a drastic jump from one tank of fuel to the next, then another jump with the next tank of fuel and now it is holding steady again at the higher levels. If the mileage had steadily risen as the average temps rose then I would be inclined to attribute all of the loss to the weather, but it didn't. This also occurred on a carbureted Jeep and a fuel injected F150 so it was spread across different types of fuel management systems. This has been treated as much like any other experiment I would do in the lab by holding as many variables constant as possible(can't control the weather, yet) and watching to see what happened. Part of the problem has to be attributable to the different fuel blend, and it seems as that is a large percentage of the overall difference from what I can determine.

I would love to have an engine on a stand in an environment controlled room and run a test with a sample of fuel from each month to really see what the difference is, maybe one day I will have that setup