BAD mpg from the Aveo

[AVE0SAM]

ours just got under 2dollars this week...

[mtlswift]

[quote=Audacity Racing]

The thing with the low gas mileage claims is...the gas has to go somewhere. there's no way gas can escape without leaving tell tale signs. See, an engine cant just eat up a ton more gas just like a person cant eat unlimited food. your stomach is only so big, so is the combustion chamer. The gas either has to leak out of the vehicle..You'd smell it when parked and likely get a cel from the computer sensing a difference in the way the tank is venting due to a leak.
Or Your injectors are spraying more fuel into you combustion chambers than other aveo's. In this case, you would still see traces of the wasted fuel as black soot and smoke from the tail pipe. It will dirty the rear bumper quick.

sorry, but your reasoning is incorrect on so many levels...

Or not... [/quote:2u4dqvcb]
First of all, OBDII systems won't let your car get away with pushing out a lot of unburnt fuel. Either the ECM will compensate, or you'll get a CEL long before you notice you have poor gas mileage. Size of a combustion chamber has nothing to do with it. If it did, by the above logic, every car with a 1.6L displacement would burn the same amount of fuel. If you have denser air, it can accomodate more fuel.
There could be a leak in the fuel system, but if it's downstream of the pump, again, it should set off a CEL. If it's upstream, you should more evap on hot days and your mileage should suffer more when it's hot, but again, you should get a CEL, cuz the evaporative emissions sensors are sensitive enough to notice a small leak due to a loose gas cap.
What should you check for? Clean air filter, good tire pressure. Then work out from there e.g. spark plugs etc.
Driver and driving habits play a huge factor in mileage. Does he have a lead foot? do high revs? Lots of stop and go? Distance travelled? weather, altitude, type of roads all play a factor. Auto vs manual tranny.
So yes, one engine can eat up a lot more gas than another one.

The big deal is this though, in city driving you don't reach closed loop... your car reads off a map. If there is a problem with the fuel system, it's not compensated for while the O2 sensor heats up. No CEL would be thrown.

Furthermore, ODBII systems will do whatever the map or sensors tell them to. If a sensor was faulty, it could pour the whole tank in the engine in a single duty cycle if the ECU felt like it. O2 sensors don't see fuel, they see temperature. You could easily be dumping fuel in the exhaust.

Also, the pressure port on the Daewoo fuel rails are notorious for leaking fuel... and there is no flow regulator on the fuel system... the ECU would have no problem with the fuel rail spitting gasoline out. The pressure is not drastically low, but the flow is high... well within operating specs.

I agree the combustion chamber size has nothing to do with it, but the context he used it in made sense. On an extreme case, you'd hydrolock from gasoline, but as far as volume goes you can only put so much in.

[khan4rtist]

WOW... it's $1.80 here

WTF, STUPID CALIFORNIA

[mtlswift]

O2 sensors don't see fuel, they see temperature. You could easily be dumping fuel in the exhaust.

they actually read O2 conc out of total exhaust mixture. By a chemical rxn it produces a voltage. to get accurate values, they need to be warmed up, but that's easily achieved after a few minutes. If you're blowing rich, rich enough to drop mpg from 30 to 20, it's gotta sense low o2 conc. If not, then fuel economy is the least of the problems.

[AVE0SAM]

24.403061807380326745115960242203 mpg is what i got this week i think its time to fix my o2 sensor and get a new filter or clean my old one....also note i have an auto and its been really cold lately so because i have yet to find or remember to plug the engine block heater in, i let it run for 10-15 mins to warm up....and even then the tranny is still too cold to want to shift out of 3rd or 2nd sometimes, so sometimes im riding for a bit at above 3000rpms..so this all adds into the bad mpg

well its great for you that are actually getting that mileage... but when i get 26mpg going hwy. or 19mpg city i get a bit frustrated. Its great that you are getting great mileage, but i'm not and you don't have to be rude about it.

I wounder if your odometer is out of wack. See if you can borrow a GPS and verify your speedo system. It would be great if it were that easy.

My Aveo gets around the same mileage. I dont measure the MPG using some silly equation...I wasnt even that good in math. I reset both my trip odometers every single time I fuel up. I have run around the city, and even making it to one other side of the city will take the fuel gage down. I can run it to empty, and the trip will read around 260 to 280. I am do drive it like a sports car and I am pretty happy with it. As they all said...MPGs are just estimates. I think it even says on the sticker "These figure may vary."

An online petition will not do anything about the MPG in our cars...what direct connection does it have? Absolutely nothing.

[ontarian_frog]

24.403061807380326745115960242203 mpg is what i got this week i think its time to fix my o2 sensor and get a new filter or clean my old one....also note i have an auto and its been really cold lately so because i have yet to find or remember to plug the engine block heater in, i let it run for 10-15 mins to warm up....and even then the tranny is still too cold to want to shift out of 3rd or 2nd sometimes, so sometimes im riding for a bit at above 3000rpms..so this all adds into the bad mpg

block heater plug right beside battery rolled up with a tie wrap if you have one.

[gsills]

this topic looks dead

but I got a 2005 Wave with 47,000 km and my MPG sucks (23mpg mostly hwy!!) ....I also have a 2003 grand am Gt and it gets better gas mileage ...it has a larger tank but I write down my figures and it works out to be better under the same conditions to and from work ...

my step brother has a 2007 wave and he gets great mpg as we work out his results

The engine is in great shape and has always had regular maintence from the previous owner ect...

you will see my other post i was looking for the fuel filter only to find out its in the tank! ...

i also checked and changed the spark plugs, air filter and i threw some injector cleaner in the tank for the hell of it