What octane gas u using?87oct 89oct 91oct and so far no difference lol

So I googled and read people going from 91 to 89oct and supposedly got a 5mpg upgrade. I'm calling bs lmao. Tried it on twice and it's about the same or slightly worst mpg than 91 and that's having a recent tune up and alignment. I have a 2004 aveo 5speed. Another thing.. I don't know or read how u suppose to calculate your own mpg but the way I done it is I wait till the low fuel indicator pops up. Then I'll put exactly 5gallons or whatever I feel like putting then after it runs out and the indicator pops up again I divide my mileage ran with the amount of gallons. Just saying because I can't see a aveo hitting 40 or even 35 in most cases unless going downhill or people not calculating mpg right. Just taking guesses. I wasn't sure what to expect from my car when I got it about a year ago but it definitely wasn't about 24-27mpg like been getting lol. More like 30 average. But oh well. It is what it is. Wish the rpm were 1000 lower in 5th gear

I always use 87 octane in the Aveo. Its simply not tuned to take advantage of higher octane so there is no benefit to using a higher octane fuel. People claiming they see better mileage out of higher octane fuel are full of it. If the engine is designed to use higher octane fuel you will see reduced mileage (and power) from using lower octane fuel, but thats not the case with the Aveo.

The correct way to measure mpg is to fill up your tank completely. I normally fill up until the pump clicks off once unless I know it turned off way too early. You reset your trip odometer at this point, and drive until you decide to fill up again. You fill up again using the same technique (1 click, 2 clicks, whatever just so long as its near full). Then you take your trip odometer reading and divide that by how many gallons you've used. That is the correct way to measure mpg.

You can't use the gas light as an indicator because its just not that accurate. How does it accurately measure gas that is constantly sloshing back and forth around in your tank? If you go uphill your light may turn off, and if you go downhill the light turns off again. It really can't measure it that accurately. Your technique may get you close, but its not going to be real exact.

40+ mpg is very possible, but not very likely to happen in LA traffic. I get 40+ mpg with my Aveo all the time, but I drive a country road to work and its 45 mph most of the way and few stop lights/signs.

Yea. I just ran out a full tank of gas and ran 293 miles till I put more gas in it. Car maybe had another gallon in it? So u haven't had knock or anything bad from running 87? I always used 91. Then just switched to 89 about 2 weeks ago. Now thinking of running 87 but was afraid it would harm engine. Maybe not at low rpms but at high ones. Not that I race but maybe once a week I'll hit redline just in first or second gear lol. So I guess I'll go to 87 if there's no harm in it? But driving my old civic hx gave me 36mpg driving the same way. Well driving 80mph in freeway instead of 70mph like in Aveo. Sure missed civic but suspension to ruff

87 is perfectly fine for all rpm ranges. The engine was designed to run on 87 and will very happily run on it no matter how you drive.

In the event you happen to get a bad tank of 87 octane (I've honestly never had a bad tank in all my years of driving) you have a knock sensor that will protect the engine and retard ignition timing to prevent any damage. So, you just loose out on some power and get worse mileage for that tank, no biggie.

Thanks. U gave me the confidence to save another 10cents a gallon. I'm thinking of upgrading to the new sonic one of these days. Well I been comparing the 2012 sonic,elantra,fiesta,Kia rio and civic hf. Thinking of getting one of those after I sell my supercharged honda s2000

All depends on the engine. I have a Dodge Ram with a Hemi and there is almost a 20% difference between running 87 and 89 octane. The engine is tuned for 89 octane. To combat the argument that higher octane = higher mpg, I get worse fuel economy with 92 octane than with 87. For the Aveo, I can't see my hamsters being performance tuned for 89 or 92 octane, so 87 is all that will ever be put in it.