Gas/Mileage issue

[SuperBuickGuy]

Two completely different cars, two different drivers (my wife, me) have both noticed a 20% drop in our fuel economy. For me my GTO went from 16s/17s mostly city driving to 13s/14s - my wifes car (the embodiment of evil) went from 50 to 41 mpg.... what gives? I'm used to the 10% reduction when they go to winter blends, but 20% and the winter blend isn't supposed to hit until November. What gives? anyone?

[Darren N.]

That's a pretty significant decrease. FWIW, gasoline blends aren't standardized so maybe your local station(s) have more ethanol in the gasoline than usual. I think pump gas can be up to 10% ethanol without any notice from the supplier. If you both fill up regularly at the same stations, maybe try another?

[SuperBuickGuy]

not only different stations (Costco and Shell) but different types of gas - unleaded/super unleaded... We have several refiners up here, Chevron, Arco and Shell

[Mater]

hmm

that is strange


has any one else at your work notice this as well? going to check the merc last i recorded it was averaging 19mpg

[Scott Liggett]

Here in Cali, my mpg goes to shit in summer with the very heavy ethanol blends.

[IOWA552SLOW]

i havent noticed this at all. i do notice a drop if i fill up at certain stations, so i avoid them at all cost. nothing wierd here at least not yet.

[studemax]

Bet it's more ethanol in your gas.....

[A/Fuel]

I haven't noticed any difference here in Indiana....
Then again, I filled my tires up like the president said and it's been working great!

[SpiderGearsMan]

E10 ...ya , great stuff

[SuperBuickGuy]

E10 ...ya , great stuff

my working hypothesis is that it's E15 rather than E10 or E5... but I was wondering if anyone had heard/knew of a formulation change... but would even E15 cause a 20% drop in mileage? Originally I thought it was just another feature of the GTO because it does have a few annoying issues (seems to drop a cylinder at 4000 rpms and above - but also could be an exhaust leak), and the rebuilt trans shifts worse than a NP435

[Beagle]

my mileage drops in the winter, I figured it was the gas but can't put my finger on it. Ut seems like it came early this year. My mileage on the highway tanked on the last couple of trips by about roughly 9-10% - about 27.5 v. the 30 I normally get. Are you guys running the A/C still? I think for me the drop is because of crappy gas along with running the a/c still. During winter, I expect mine to go UP from not running the a/c constantly and it goes DOWN.

I also wonder about the suppliers. I went through Oklahoma a couple of years back and they proudly displayed signs that said "Our gas doesn't have ANY damn alcohol in it" even though the pumps said "up to 10%"

Maybe they weren't putting much in to start with, but now they're actually putting the 10% in? We need an FDA for Gasoline? Truth in advertising? My food has to be disclosed, maybe my car's food should have to have full disclosure too.

BBR mentioned picking up a headwind and it wiping out the Durang's mileage. I usually pay attention to the wind so I can see if that is what's causing it. It does hammer my Lightning, but the Escape doesn't seem to care as much. Maybe because I drive it slower. haha. That hasn't been the cause on the last couple of tanks though.

[gearhed1971]

It should be even more of a challenge for the car manufacturers who are mandated to achieve a certain mileage standard. Why are the oil suppliers not held to the same standard?

[SuperBuickGuy]

my mileage drops in the winter, I figured it was the gas but can't put my finger on it. Ut seems like it came early this year. My mileage on the highway tanked on the last couple of trips by about roughly 9-10% - about 27.5 v. the 30 I normally get. Are you guys running the A/C still? I think for me the drop is because of crappy gas along with running the a/c still. During winter, I expect mine to go UP from not running the a/c constantly and it goes DOWN.

I also wonder about the suppliers. I went through Oklahoma a couple of years back and they proudly displayed signs that said "Our gas doesn't have ANY damn alcohol in it" even though the pumps said "up to 10%"

Maybe they weren't putting much in to start with, but now they're actually putting the 10% in? We need an FDA for Gasoline? Truth in advertising? My food has to be disclosed, maybe my car's food should have to have full disclosure too.

BBR mentioned picking up a headwind and it wiping out the Durang's mileage. I usually pay attention to the wind so I can see if that is what's causing it. It does hammer my Lightning, but the Escape doesn't seem to care as much. Maybe because I drive it slower. haha. That hasn't been the cause on the last couple of tanks though.

good point, but that's only 10% of the mileage issue.... also, as a side note, we've had like 2 80 degree days here - so A/C is rarely rarely on...

I'm seriously considering driving my diesel pickup (20 mpg)...

[Barry Donovan]

there might be something to this gas stuff..

I have an 87 engine, crazy egr cams. Forced to change cams due to no timing possible, no retard or advance allowed it to be normal. Just yesterday. after 9 months of retard knock. Blew a gasket in december.

I seem to be more diesel than ethanol. unless it is same result? less octane?
dunno.

cams with more duration get over the crazy fuel. At least you just notice bad fuel mileage and keep running. I encountered not even runnable.

[happy39]

No question they are screwing with us. I noticed that my F150 mileage has gone down as summer season hit. I even added a new K&N air induction and filter combo. I am sick of the oil companies playing with us. No one can ever tell me they are not all in bed when it comes to setting prices and offering the same product. Oh how I miss the days of companies trying to get you to buy their product by making it better than the next guy.