sddale

Last weekend I made a trip from Madison to Chicago and on the way down (highway only) the best I could get was 35 MPG on BP premium (either 91 or 92 octane) with "up to 10% ethanol" stated on the pump.

On the way home I filled up with Shell 93 octane (I believe it's ethanol free) and for a stretch of about an hour I got 39 MPG. I know that it's only an hours worth of drive time but it's still pretty good. It was killing me driving that slow and after an hour I had to speed up.



How much of the difference do you think the gas made? Do you think it's worth filling at an ethanol free station? There are only a couple around my area and they're priced about 10-17 cents more per gallon. I'm not sure if it will give 10% better mileage with city driving.

ttribe

No such thing in Arizona. Ethanol additives are mandated by law here.

SharksBreath

iTrader: (33)

when you got 35MPG on 91/92, how long were you driving for? that 39MPG might just be because it was a steady speed/1 HR drive time.

i only use shell Vpower, i haven't even been to another gas station since i've owned my TL. i don't think that 10% really matters all that much.

sddale

The total time was almost 2 hours but it was pretty consistent at 35 and never showed 39.

VQPower37

im sure the 10 percent made the mpg difference, i wish there was an ethanol free gas station in my area but the nearest one to me is about 200 miles away

SimonCL-S6

I used to always fill up my CL at bp, now i started filling up at shell and the gas mileage has improved

Ken1997TL

There are a couple here in my area, I fill up there when I can.

jpgayan

Ethanol has about 70% of the energy content of gasoline. Hence, the 10% ethanol has about 97% of the energy of regular gas. Newer cars are supposedly designed to deal with the down sides of ethanol, I think it can be more corrosive to certain valve seals, but if I can find an Exxon/Mobil that's got ethanol free gas for comparable prices I try to fill up there.

EL_PIC

Ethanol will decrease mpg, hp - and often a octane loss.
It increases corrosion and fouls up the injectors.
Its only got about half the explosive energy of gasoline
even tho the octane might be higher.
Ethanol in its purest form is like 110 octane
but its demise is H20 absortion and purity logistics.
That means water in your tank and corrosion in engine.
Overall your octane might be lower with some unknown amount of H20.
Check out Brazil's problems with 20 - 20% sugarcane ethanol.
LMAO - GM's 85% flex fuel cars !

But in Ethanol's defense ...

Its got the US Govt tax dollars backing
with strong corn mid west support.
Congress loves it !!
It has its own corporations, stocks and strong political lobby.
Its better than previous used MTBE which they found
to be toxic and cancer causing after using it a few years.
Of course ethanol may also be toxic but shhhh ...
its a money making secret.

JTS97Z28

iTrader: (4)

No ethanol free gas here around chicago for atleast a decade. Either way my TL-S gets better than advertised fuel economy so it cant be all that bad. Would I rather have ethanol free gas? ofcourse, but people make it seem like its going to ruin your engine, cause horrible fuel economy, and reduce power. It does none of that.

James

sddale

I thought that Chicago stations all had ethanol but wasn't sure if that extended out to the suburbs which is where I filled up.

JTS97Z28

iTrader: (4)

There is no ethanol free gas in the Chicago area city or burbs. And if there is please say which ones do have ethanol free. None that I am aware of.

James

05AcTL

iTrader: (15)

^I cant think of any

3gstealth

iTrader: (2)

Here is a pretty comprehensive list of the ethanol free gas stations: http://pure-gas.org/

Looks like I have a couple of options near me. I will have to give it a try

ashdec87

Ok slightly off topic, but how are you getting 35-39mpg? Best I've been able to do is 32 cruising at ~70.

Back on topic. BP definitely gives lower mileage compared to Shell. I also believe that the gas stations are switching back to their 'summer' blends as one day my gas mileage shot up substantially (always drops in the winter...)

sddale

Just slow down to about 60. It's painful to do but I was curious on how good the mileage could be. We're probably about the same at 70.

wise_optimist

This!

I believe all MD gas stations are also required to do "up to 10% ethanol".