BUSTED: why some of you complain about you car's performance on E85

[HoosierRon]

Today in World Opinion: “We are not getting gas that starts out as 87, 89, or 92 [octane]…it is obviously bad for the consumer who doesn’t know any better.”

He informed me that in many cases the oil companies are blending the ethanol with gas that is 85 or even 83 RON. We are not getting gas that starts out as 87, 89, or 92 RON and then ethanol added, which we know should improve performance. This would explain why motorists are reporting a greater than expected loss in MPG’s; especially at E85. While this is clearly a way for the oil companies to cut corners and make more money it is obviously bad for the consumer who doesn’t know any better”

[davidlane]

Originally Posted by HoosierRon

Today in World Opinion: “We are not getting gas that starts out as 87, 89, or 92 [octane]…it is obviously bad for the consumer who doesn’t know any better.”

These same consumers, "who don't know any better" are probably the same ones that vote for legislators that "don't know any better" and force junk science/bad solutions on those of us that have a clue. Trusting a free market to work would be far to simple and reduce the possibility of buying votes from the uninformed while keeping their cushy jobs!

[jpm100]

I'm more concerned about what we are really getting with E10. Ethanol is great stuff for making for smooth combustion. Even a little bit can cover up crap gas.

[Generous Motors]

Consumers are complaining of lower MPG, and the writer is contributing it to the base gas being of 83 RON??? This is another case the uninformed internet experts, lowering the octane will not effect the MPG, beside ethanol will raise the octane of that base stock 83 RON to well over 93 when it is E85. The loss of MPG is due to the lower BTU's of ethanol over gasoline.

[Smaart Aas Saabr]

Yeah octane loss? That doesn't make sense.

[nailhead425]

While true, 10% ethanol can boost bad gas to 87 octane, in the midwest most of the cheap-gas is either 89 or 90 octane and 10% ethanol.
87/88 octane gas is midgrade, and 91-93 is premium.

If all things are right, about a 5% loss in mileage when using Ethanol blend.
About 30% mileage loss with E85.

[vsd]

Lower octane doesn't lower mpg, just as higher octane doesn't increase it. All it would do is cause the engine to knock, and eventually break.

[brianidaho]

The original article qouted someone that is ignorant of anything involving engineering or combustion engineering. Of course you'd start with a lower octane gasoline, as other posters have said the ethanol raises it anyway. Increased octane above the level required to prevent pre-ignition doesn't help, and may hurt fuel efficiency.

The problems with E85 in dual fuel engines is that ethanol has a lower heat content, and the compression ratio of today's engines optimized to run on gas, does not get the most out of the energy in ethanol. I believe compbustion temperatures are also lower, leading to efficiency losses.

[2005 Equinox LS]

I havent tried E85 in the Impala yet. I probably wont in the near future since it doesnt seem economicly advantagious to do so.

[Prince Valiant]

For the most part, my brother's Sebring (2004) runs noticeably stronger on E85. Sure, it produces ~ 30% less energy per content, but then you run ~40% richer mixture thus off-setting the energy loss, and actually showing a mild gain. This is why many dyno-test documenting both fuels shows that e85 consistently makes more power/torque than the exact same engine running on gasoline.