Has anyone else here noticed that their car isn't getting as may miles per gallon as it used to? Mines dropped about 5 mpg since they started putting ethenal in the gas.

Yeah, I've read that's the tradeoff-the fuel is cheaper (usually), but you don't get as good a mileage with it.

Aren't they supposed to tell you that there's ethanol in the gas? I'm getting lower gas mileage because my car is 12 years old and has more than 160,000 miles on it, and I'm sure the gas tank is getting corroded. My gas mileage has dropped from 40 mpg to 38 mpg.

I'm pretty sure that the gas I put in my car has no ethanol.

Time to switch to diesel bio-fuels...

Ethanol has a lower energy content than gasoline, therefore more has to be burned to attain the same power output. An E85 vehicle has a drop of up to 25% in mpg when not using straight gasoline.

I don't know if it's state or federal law, but here anyway the pump has to say the gas contains ethanol if the level is 10%. Could be 5%, but I think it's 10%.

I've noticed that my gas mileage, and the performance of my car, hasn't been as good since gas prices hit about $2.50 a gallon quite awhile ago.

I mentioned this to my brother-in-law, who delivers gas for a living, and he told me that we were getting worse gas and paying more for it, though that is admittedly anecdotal evidence, and I didn't get more information from him to tell me how he knows this.

When I was a kid, I worked pumping gas at a local station that had been owned and operated by the same family for many decades. Though I don't recall the details of such conversations, I remember being given the very strong impression that the gas distributed to your local station was done so very indiscriminately and that the differences between gasolines that were marketed to the public, had little basis in reality. At the time, this meant that unleaded gas wasn't necessarily unleaded, 93 octane might very well be 87 octane ( or even vice-versa), and the gas you got at Mobil might be the same exact gas you got at Getty, Texaco, or anywhere else. Again, this is was a long time ago and its purely anecdotal.

Winston,
If you're getting worse gas mileage it's possible ethanol is now in your gas. I think 10% alcohol causes a 3% decrease in mileage.

If you pay for 93 and you're getting 87, the gas station is cheating you. They have the tanker driver pump 87 into the 93 storage tank and then get 93 octane buyers (me) to pay 20+ cents more for the same thing. It's not that uncommon. I have a thing for my car that reads knock counts so if it ever happens to me I should catch it.

Gasoline is gasoline. The different retailers, Mobil, Shell, etc., add their own additives, but the tanker trucks all get their gas from the same spigot.

Because I just realized this thread is off-topic, let me say I support the no smoking rules while refueling.