THANK YOU 'toomuchrock'. Well I am not alone...but I knew that:) For such a tiny car,with a tiny engine,that barely weighs just over 2,000lbs, it should get high 30's in the city and higher on the highway.! Automatic or not. My 'big' Ford Ranger pickup with a 3.0 liter V-6 got 15mpg in the city,if I drove like a nut or like an old lady. I traded in my beautiful screaming yellow Edge truck,for an 'economy car' that I thought was kind of cute, roomy, and thought would be economical. The thing to do when gas was going into the upper stratosphere! By now my truck would have been paid off, and the price of gas would be no big deal now. I should have kept it. It isn't worth 5 years of payments for 2-3 mpg more. I thought I would get upper 20's at least in the city. Like I have said, 18mpg is the best, if I drive VERY VERY carefully, and this is after my oil changes and spark plug change. GM has no intention of fixing anything. As long as they manage to get their 'CAFE' numbers to come out to the numbers they can prove in 1 car to the government. They will crow about these high numbers and ignore the real world numbers. BUT I love my little car,all the room and the automatic tranny. It's only main problem is poor mileage and that damn drivers door that wont lock without the key! And of course more power would be nice. BUT it is what it is. And we think we are buying a car to save gas and get OPEC out of our wallets a bit. But this little improvement in mileage,isnt going to do much on that front!
Just got back from a trip through the Ozark and Ouchita mountains and I got 33.8-37.2-36.3 on 3 tanks of gas......not to bad driving thought the hill of Arkansas and Oklahoma and back to East Texas. Let my mother drive from from Canton Texas up highway 19 to interstate 30 to Texarkana and up 259 to Mena Ark.....that is where the 33.8 mpg came in as she was going between 70-80 mph at some stretches....and got higher mileage on the little back road of 37.2 and in Hot Springs and in the hill and back over to Fort Smith....last leg ot the Trip was on a Tank of gas we got in Mount Vernon Texas headed back home...to Kemp Tx....mpg was 36.3.
a very cool place to visit. Living there would no doubt be fine, too. Too hot and humid and the possibility of tornado's caused my wife and I to head back west after graduating college.
Yeah, 70-80mph will stomp all over decent gas mileage!
Yeah, 70-80mph will stomp all over decent gas mileage!
You are not kidding.....and I hate ethanol,,It give lousy mileage....every summer here in Dallas my mileage falls off like a stone...drive out to visit family and I wait to get out of the surrounding counties to get gas were they dont use the blended version and my mileage is great.
Just over 17500 miles. My one year average is 38.71 mpg. Sure beats the F150 I sold for it. Appox 8900 lbs of carbon not in the air from me. Only mod has been a K&N filter because no one sells the OEM one.
I've had my Swift one month now and it should be sold by the weekend. Terrible gas mileage. 18-20 mpg 3 fillups in a row. City driving, yes, but it's a demo with 7000 km on it so it should be broken in. I'm glad I didn't sell my old Honda.
I have a 2006 Aveo Sedan which I bought as a left-over recently with 43 miles. This may sound a little hard to take....and I had to do the math again myself....BUT I drove from Orlando, FL. to St Petersburg, FL and back (about 75-125 miles one way) on a quarter tank of gas. I almost sh*t myself! I was cranking almost 50 MPG. The car had less than 1000 miles on it at the time. Is this going to change? :shades:
The best tank I have had with mine has been 43.5 mpg. Accroding to my math, between engine displacement and weight, It was the best I could get. If you are less then my 295 lbs, drive a constant 55 mph and never shifted above 2000 rpm's it could be possible. A quarter tank on mine (with the needle on 3/4 tank) is 3.54 gallons. I normally get 140 miles. The aveo is a warm weather car getting the best mileage when the temperature is over 55 degrees. Mileage on mine has been great since I bought it, so it should hold up for you, 18000 miles so far and it has great, 38.71 mpg average for the year.
The only true way to get accurate gas mileage numbers is to start with a full tank, put the miles on and then refill the tank (preferably at the same station and pump because they differ in fill-up level).
Divide the miles traveled by gallons used for your mpg. Using the fuel gauge, especially in a car that's new to you, can be misleading since it's not linear -- you won't get 4 times your 1/4 tank miles on a full tank.
It's also essential to use several tanks worth of mpg numbers for the truest figure to account for an air pocket when refilling or pumps that shut off early.
50 mpg is incredibly high for this car -- have heard of low 40's under the best conditions, so I'd give it a few more fill-ups using math to calculate -- not the guage.
We just put our first tankful in our 2007 Aveo. The MPG was 30 on about 50/50 city/highway driving. My 4 cyl MT 2003 Ranger got 31 MPG out of its last two tanks, so I'm a little disappointed. We're hoping the Aveo does better once it's broken in and my wife gets used to the manual transmission.
It sounds like something's off in some of the cars considering the variations in gas mileage described here. If you have a manual trans. like I have, you should be able to get at least decent mileage by keeping the revs between about 1500 and 2800(except when you need to go over 60). In any case an Aveo should get better mileage than the 6 cyl '78 Dodge Aspen I had when I was a kid. If the dealer has already checked the computer which _should_ pick up engine troubles such as bad sensors and misfires, you might want to look for problems elsewhere on the car (or maybe for a different dealer.)
After looking at the forums two other possible explanations occurred to me. The MPG differences reminded me of a car I owned whose parking brake didn't release properly-once I discovered the problem & got it fixed, city MPG went up 20%. The other thing that occurred to me after reading some other threads about suspension and tire problems is that the alignment might be off on some cars. I think extra toe-in on your alignment helps your car drive straight but is an MPG and tire killer. These ideas are just SWAGs from a shadetree mechanic who thinks you should seek profesional advice if you are getting less than 20 MPG from this car.
I also live in Florida. Orlando to be exact in the tourist area (by Universal Studios). I have to travel to Altamonte Springs on I-4 to get to work. I would say that I am driving 5 miles to I-4, and 5 miles off of I-4 to work. I only fill my tank once every two weeks. We also use my car when we take trips around town to the grocery store, out to eat, etc. However, the Sunday after I took delivery of my Aveo, we drove from Orlando to St. Petersburg to see some friends and I got just a hair less than 50 MPG doing an average of 65 on I-4 and 275 using regular unleaded gas. I was impressed. I have a 2006 Aveo LS Sedan 5-speed and use the A/C like there is no tomorrow. I purchased it as a left-over vehicle in April 2007.
Don't change the oil until you reach 5000-7500 miles?!?!? The manual says every 3000-5000 depending on driving conditions. Timing belt needs replacing every 60K. i would go back to the dealership and request to have that person's head examined! LOL.
I'm in Canada (Vancouver) and I've got a new 2007 Aveo Sedan. I've been averaging about 40 MPG (imperial gallon) with mixed freeway and city driving after about one month of engine break-in. Yeah the gas mileage on the first tank was about what you were getting (about 34 mpg)....but it seems to be improving with age.
The car is more broken in now. The 2007 hatchback (manual trans) is getting around 37mpg (US gallon) in mixed highway/city driving. Best tank was 42 mpg all highway. We are pretty lighfooted drivers so YMMV.
"I drive in this car the same way i did in my 2000 Cavalier and i got and average of 30MPG out of the cavalier and its only rated 23-31. Driving the same exact trips the same way i get about 24mpg out of the 2006 Aveo when it's rated 26-34. Someone please explain how this is possible at all."
Sorry about the mileage. There was some posts in the regular Aveo forum from about a-year-ago regarding some Aveo's that were getting low mpg that just needed the cpu flashed with software. It may be just a software correction.
lol well they have yet to flash my cpu, and my mileage is still poor.... i've asked them to flash it on 3 seperate occastions. What, pray tell, do you suggest I say to my dealer to get them on the ball. As i am currently averaging between 18-25mpg in my 2006 aveo.
they say almost exactly "there are no recalls, or TSB related to your mileage problem" I last year i took it there 5 seperate occasions about the mileage problem specifically. Any time I have to take it to the dealer for anything I always mention the poor mileage. There are no other chevrolet dealerships near where i live. I'd have to drive 30+ minutes away, and be without a car to drive while they attempt to resolve the problem.
You probably already have but if not, take a good look at your fuel injection unit on top of the engine. Make sure that there are no vacuum hoses or anything that has come off. I read on some other forums that an easy way to get the warning light to come on for the plug-in diagnostic is to losen your fuel cap. This may give the dealer no choice but to give your car the once over to see if anything is out of place. Just a thought. I would be p/o'ed to. I am sure you don't race it and keep the tires at the correct pressure.
I am so disgusted I could be sick. We purchased a 2007 Aveo LT sedan, trading in my 2003 Cavalier, which I was getting 33 mpg's on the highway, little less in town. The sticker said 27 town 37 hwy. I have gotten 16 town and 27 highway. I have called the dealership, and had it put on the machine, so they tell me they do that anyway, wasn't back there. Claimed it was doing everything it's supposed to do. contacted GM, and they're aggreeing basically with the dealership, that it could be the ethinol that's causing low gas mileage. I tell you what I would NEVER purchase another one. They don't even want to make it right with you. They've sold their car, who cares?! I was on an open road, I-10 west, and got a measley 27 mpg. Makes me sick that I've traded my cavalier in on this piece of junk. There are times when I have to gun it, because I don't care to be ran over by vehicles driving all over you..
Of all the cars in the sub-compact category (Yaris, Versa, etc.) the Aveo gets the worst mileage. In fact my 06 Caravan with twin cam 4 cylinder engine (2.4 liters) gets better mileage.
What makes me even madder, is they tell me it's the enthanol in the gas. I've been here four years, used ethanol in my cavalier, and got good gas mileage in that. Why is it, that nobody tells you these things about these cars , and use false information about them on the window sticker. ??!! I've gone to GM, and all they're telling me is that it's the ethanol causing it. Who else do I turn to for help on this? I don't think I've read anywhere on here that anybody's gotten as bad of gas mileage as I have. Makes me sick..
JFP. With the exception of the FEW that drive all day on the highway. We ALL get crumby mileage. I dont understand it. Since day 1, I have been complaining about it,..and then someone will post that they just got 39 mpg on their last trip to Tenn. or someplace. For a car the weighs next to nothing, and engine that puts out only 103 hp at most! And considering it is fairly aerodynamic, you would think it would get 30 in the city all the time. THATS why I bought it! Bud, when I get 19mpg, I jump for joy. I plan my trips to make it as long as possible, to get the car to run hot and use the gas as efficently as possible. By running it in long errands, that is the only way to get any mileage out of it. And that is only 18-19mpg! Welcome to the club. I am hoping that what it lacks in mpg, it will make up in an engine that lasts for 500,000 miles! Or at least the parts on and in it will last till I trade it in on my next TRUCK! Might as well have fun if I'm going to get a pitiful 16mpg 99% of the time!
Problem is, who do you talk to about it? Service reps, have it made in the shade, cause GM believe anything they say. They're their eyes, and ears, they say. I just bought mine four months ago, and have gone 1900 miles in it, and it's gotten anywhere from 15-highest 19 in city. On the highway I got 28, when it was supposed to be 37. Is there nothing us as consumers, can do about the false advertising they do, to sell these cars.?? Ya know I'm about ready to go to bigger car myself. My husband had a Nissan maxima, and got better gas mileage, and he had 80,000 miles on it. Nobody's going to give me what I paid for that car, on a trade in. The depreciation is too great. I am stuck with this piece of garbage for three years tops.
I just picked up my 2007 Aveo 5 last week and I read in the owners manual that I should not use gas with ethanol! WTF? Where can you get gas WITHOUT ethanol? Certainly, there is significantly less energy in straight ethanol but to the best of my knowledge the max amount in regularly available gas is 10%. Anyway, my very first tankful was 29 around town and I am happy with that compared to my 04 F-150 at 16 mpg around town. Hope to get better when it's broken in and I put full synthetic in the engine at the first oil change. I drive the car easy, but not like an old lady.
Drove from Plano texas down to Kemp. Picked up my brother and we went on to Tyler drove around the city did our little chores and got ready to head back. Stopped and filled the tank it took 5.2 gallons....drove 194 miles......I think that is pretty good. Oh and 5.2 gallon is all I could get in the tank.....
I would start by filing complaints with consumer groups and agencies. For example, the Better Business Bureau or some state government agency. When your actual miles per gallon is way off from what the manufacturer says, then the manufacturer is providing consumers with misleading or false advertising. If enough people complain, maybe something can be done about it. Good luck.
Nordy, here in Illinois gas has had 10% ethanol for at least 10-years. I haven't seen the manual. Are you sure it wasn't talking about E85? That sounds kind of odd.
My bad; I just checked the manual and it was referring to methanol. GM does in fact recommend the use of gasoline with up to 10% ethanol, if it complies with "Top Tier Detergent Gasoline" specifications. Page 268 of the 436 page owners manual. My eyes started glazing over when I started reading the manual; I can't beleive that such a small inexpensive car has such a thick manual!
I'm going to look in my manual. There's supposed to be something in there, that says if you're not satisfied, to contact such and such, my husband says. It's sad when you're lied to like that..unfortunately we're all blessed with being a sucker when it comes to getting something that saves gas.
After reading several pages of owner reviews, it appears that many are getting gas mileage far below what they expected and/or what was advertised.
I'm afraid to ask but does anyone own an Aveo with the four-speed auto transmission or is that just a given "no-no?" What is anyone getting mileage-wise out of the AT? How badly does this AT effect performance?
I have an automatic. I mean it's already a cheap car..getting a stick is WAY to cheap. It is only $810 more. One of the FEW luxuries it has. And it doesnt cut into the mileage numbers on the sticker all that much. Who wants to shift constantly in city traffic. It is only one of the few things that makes driving it a pleasure in the city! My truck was a stick, and it was just a pain constantly shifting. I will never get a stick car or truck again.You only get 1-2 extra MPG...and in this car....that ain't saying much! I beat nearly ever stick car that I know I am next to at a stop light. I don't even have to'gun it'. I beat all the Sentras,Civics,and other subcompacts, that have sticks. At least the ones that are 2-4 years old. The new ones...it's pretty even.
I hear you about the transmission issue. I have an automatic in my 04 F-150 and it is the easiest driving, smoothest shifting vehicle I have ever owned. Actually, when the new F-150 first came out, it was not even available with a manual. I am one of those who actually like to drive a stick, especially in a small FWD car like the Aveo. I have to say, it has a really smooth and easy to use clutch/gearbox for such an inexpensive car. Driving my motorcycle in traffic, now that is a PITA.
I had the same problem trying to find the sticker with the psi on it. On mine it is located on the bottom of door jam on the car (not the door) along the floor board. BTW - it is 30 psi all the way around.
For Grace4ever: I know everyone will jump on my back for this comment, BUT to get that 1-2 extra mpg out of the car, I have all my tire at over 35psi,and they are nitrogen filled from the dealer. The 'harder' ride feels more German,like a VW or a Mercedes, I like it and so far after 1 year, at over 35psi..I have no wear in the center. The entire tire has given me trouble since the first month, they wear out fast at any psi! But you ride at what make you comfortable. But the higher the pressure, the less gas you use. And I think the ride is better and you dont feel like your dragging a trailer! At that low 30mpg,it sucks up gas. The harder the tire, the easier it will roll, the less gas you use. BUT it will make the center wear out somewhat faster. But factory tires are crappy anyway on our Aveos, so who cares! If you ride at 30psi...the sides will wear out faster. So no matter what, they wear out fast! They are such low quality tires,you need to replace them probably in a year or two,if your lucky, and put on something with a known name, and a long warranty. These are only 'good for' 20K miles! Thats how crumby they are.
As far as oil changing goes. The standard is 3 months or 3,000 miles. Your manual will tell you the exact time or mileage. It depends on if you drive in the city all the time like I do. Or on the highway all the time,or a mix of both. Using synthetic oil will extend the changes up to 5,000 or 10,000 miles! BUT I think no matter what kind you use. It is VERY cheap insurance to change it more frequently,the 3 months/3,000 miles. The cleaner the oil,the less wear in the engine,the longer it will last. And keep the proof that you change the oil, so that IF any problem pops up in the engine, you have proof that you changed the oil at the recommend time, so they cant say that you didn't follow the oil change as the manual says.
IF you do it yourself,go to JiffyLube, or go to the dealer. Just keep the receipts! IF you do it yourself, it is so easy, after you get off the first filter from the factory, that one is on SO tight it is unreal! It took me an hour to get it off! After that is off, it is very easy to do yourself, and cheap to change it yourself,as little as $12.00,if you find regular oil on sale. Up to $30.00 for synthetic oil,which will last much longer and gives you about 1-2 mpg more. The dealer charges the most,$30 for regular oil and filter,and up to $70 for a synthetic oil change! I couldnt belive that!,JiffyLube is in the middle price wise, so is Sears, but doing it yourself is the cheapest and you know for sure what is going into your car!
You are so right about the tire pressure-I recently checked the tire pressure in my truck for the first time in about a year and set it a 40, which is 2 lbs above recommended. Guess what? my mileage went from 13 to 16 mpg around town and has stayed there. My personal recommendation is to use full synthetic and change it at 5K. 3K seems a little too soon to change Mobil 1.
Some cars believe it or not get better mileage with an auto transmission. I have read that the Aveo's auto because of its gearing is supposed to be 1 mpg better on the highway. A manual though would most likely have better acceleration.
Go to the consumer rating at the top of the Aveo forum and see what others are saying with both manual and auto.
Got 30.5 mpg on my third fillup in my 07 hatchback. I'm pretty happy about it; this was city driving, with just a little highway driving. I am finding I don't have to drive the car hard to get around, it drives just fine and has adequate power. For a tinny little econobox that is.
Then you have truly been blessed. I drive mostly in town, so that could be the problem. But still it shouldn't be any 10 MPG difference. I get 15-19 in town, and 28 on highway.Sad..I wouldn't buy another one that's for sure.
:confuse: I have a 2007 AVEO LT Sedan 5speed and have been keeping tabs on the gas mileage. I average about 70% freeway driving and the rest is city. The AVEO averages about 7.4 litres of fuel consumed for every 100km of travel (that's about 38 MPG Imperial Gallons or about 35 MPG USA Gallon). So to hear people get only 15-19MPG in the city and 28 on the freeway is very strange.
I am a new user to the forum. I just leased a 2007 Aveo 5 LT automatic and after 1000 km I am averaging between 30-33 mpg based on a split of 80% highway 20% city.
Realistically this is the mileage I expected. I generally assume the real world mileage is only about 75% of the EPA ratings.
The problem is to the one that said strange..that's ALL I'm getting. 15-19 mpg city..I guess nobody believes me..reciepts to prove it...what's even sadder, is the company won't do a thing about it. Saying there's nothing wrong with the car. You know how it is, when you're a woman, if you are. They pull the wool over your eyes, and we're not allowed in the bays where they look at them or service them..
There are certain parameters that a car company follows and unfortunately whether you by a Chevy or a Toyota there is only so much they can do. I have seen this on Japanese forums as well, and there is even a Honda Civic hybrid owner suing Honda because his hybrid only gets 33 mpg, go figure.
If you are spending a lot of time idling in stop and go traffic with the A/C on that may be all that you'll get.
Otherwise my best guesses would be that either you have a hanging brake or a bad (temperature?) sensor or computer that is keeping your engine in open loop mode (open loop is the default operating mode your engine uses at start-up before it reaches normal operating conditions where it can compute fuel/timing settings to optimize engine power and economy.) Your mechanic is probably too lazy/busy to actually warm the car up and drive it with a scanner hooked up to see what's actually going on. If he hasn't done that IMHO he hasn't done his job.
I am guessing that you need to find a different mechanic/dealer--one who knows something about cars.
We are getting mid 30's around town and low 40's on the highway out of our Aveo.
Comments
My wife and I vacationed on Bull Shoals Lake in Arkansas while I went to college in Rolla, MO.
Two things I don't like about that region:
1) the humidity
2) tornado's
Anyhoo-you got pretty good mileage in your Aveo on that trip.
2021 Kia Soul LX 6-speed stick
We would stay on Lake Ouchita by Hot Springs or go up to Eureka Springs.
Living in Texas I am used to the Tornados and the humidity...lol.
Yeah I think I got pretty decent mileage out of the car condsidering on Interstate 30 to Texarkana my mother was driving between 70-80 mph.
Yeah, 70-80mph will stomp all over decent gas mileage!
2021 Kia Soul LX 6-speed stick
You are not kidding.....and I hate ethanol,,It give lousy mileage....every summer here in Dallas my mileage falls off like a stone...drive out to visit family and I wait to get out of the surrounding counties to get gas were they dont use the blended version and my mileage is great.
Just over 17500 miles. My one year average is 38.71 mpg. Sure beats the F150 I sold for it. Appox 8900 lbs of carbon not in the air from me. Only mod has been a K&N filter because no one sells the OEM one.
Ron
Charles
The best tank I have had with mine has been 43.5 mpg. Accroding to my math, between engine displacement and weight, It was the best I could get. If you are less then my 295 lbs, drive a constant 55 mph and never shifted above 2000 rpm's it could be possible. A quarter tank on mine (with the needle on 3/4 tank) is 3.54 gallons. I normally get 140 miles. The aveo is a warm weather car getting the best mileage when the temperature is over 55 degrees. Mileage on mine has been great since I bought it, so it should hold up for you, 18000 miles so far and it has great, 38.71 mpg average for the year.
Ron
Divide the miles traveled by gallons used for your mpg. Using the fuel gauge, especially in a car that's new to you, can be misleading since it's not linear -- you won't get 4 times your 1/4 tank miles on a full tank.
It's also essential to use several tanks worth of mpg numbers for the truest figure to account for an air pocket when refilling or pumps that shut off early.
50 mpg is incredibly high for this car -- have heard of low 40's under the best conditions, so I'd give it a few more fill-ups using math to calculate -- not the guage.
you should be thrilled with that kind of mileage!
After looking at the forums two other possible explanations occurred to me. The MPG differences reminded me of a car I owned whose parking brake didn't release properly-once I discovered the problem & got it fixed, city MPG went up 20%. The other thing that occurred to me after reading some other threads about suspension and tire problems is that the alignment might be off on some cars. I think extra toe-in on your alignment helps your car drive straight but is an MPG and tire killer. These ideas are just SWAGs from a shadetree mechanic who thinks you should seek profesional advice if you are getting less than 20 MPG from this car.
I hope this helped.
I'm in Canada (Vancouver) and I've got a new 2007 Aveo Sedan. I've been averaging about 40 MPG (imperial gallon) with mixed freeway and city driving after about one month of engine break-in. Yeah the gas mileage on the first tank was about what you were getting (about 34 mpg)....but it seems to be improving with age.
Sorry about the mileage. There was some posts in the regular Aveo forum from about a-year-ago regarding some Aveo's that were getting low mpg that just needed the cpu flashed with software. It may be just a software correction.
As i am currently averaging between 18-25mpg in my 2006 aveo.
I last year i took it there 5 seperate occasions about the mileage problem specifically. Any time I have to take it to the dealer for anything I always mention the poor mileage. There are no other chevrolet dealerships near where i live. I'd have to drive 30+ minutes away, and be without a car to drive while they attempt to resolve the problem.
Welcome to the club. I am hoping that what it lacks in mpg, it will make up in an engine that lasts for 500,000 miles! Or at least the parts on and in it will last till I trade it in on my next TRUCK!
Might as well have fun if I'm going to get a pitiful 16mpg 99% of the time!
Anyway, my very first tankful was 29 around town and I am happy with that compared to my 04 F-150 at 16 mpg around town. Hope to get better when it's broken in and I put full synthetic in the engine at the first oil change. I drive the car easy, but not like an old lady.
I'm afraid to ask but does anyone own an Aveo with the four-speed auto transmission or is that just a given "no-no?"
What is anyone getting mileage-wise out of the AT? How badly does this AT effect performance?
Thanks!!
I am one of those who actually like to drive a stick, especially in a small FWD car like the Aveo. I have to say, it has a really smooth and easy to use clutch/gearbox for such an inexpensive car.
Driving my motorcycle in traffic, now that is a PITA.
The 'harder' ride feels more German,like a VW or a Mercedes, I like it and so far after 1 year, at over 35psi..I have no wear in the center. The entire tire has given me trouble since the first month, they wear out fast at any psi! But you ride at what make you comfortable. But the higher the pressure, the less gas you use. And I think the ride is better and you dont feel like your dragging a trailer! At that low 30mpg,it sucks up gas. The harder the tire, the easier it will roll, the less gas you use. BUT it will make the center wear out somewhat faster. But factory tires are crappy anyway on our Aveos, so who cares! If you ride at 30psi...the sides will wear out faster. So no matter what, they wear out fast! They are such low quality tires,you need to replace them probably in a year or two,if your lucky, and put on something with a known name, and a long warranty. These are only 'good for' 20K miles! Thats how crumby they are.
As far as oil changing goes. The standard is 3 months or 3,000 miles. Your manual will tell you the exact time or mileage. It depends on if you drive in the city all the time like I do. Or on the highway all the time,or a mix of both. Using synthetic oil will extend the changes up to 5,000 or 10,000 miles! BUT I think no matter what kind you use. It is VERY cheap insurance to change it more frequently,the 3 months/3,000 miles. The cleaner the oil,the less wear in the engine,the longer it will last. And keep the proof that you change the oil, so that IF any problem pops up in the engine, you have proof that you changed the oil at the recommend time, so they cant say that you didn't follow the oil change as the manual says.
IF you do it yourself,go to JiffyLube, or go to the dealer. Just keep the receipts! IF you do it yourself, it is so easy, after you get off the first filter from the factory, that one is on SO tight it is unreal! It took me an hour to get it off! After that is off, it is very easy to do yourself, and cheap to change it yourself,as little as $12.00,if you find regular oil on sale. Up to $30.00 for synthetic oil,which will last much longer and gives you about 1-2 mpg more. The dealer charges the most,$30 for regular oil and filter,and up to $70 for a synthetic oil change! I couldnt belive that!,JiffyLube is in the middle price wise, so is Sears, but doing it yourself is the cheapest and you know for sure what is going into your car!
My personal recommendation is to use full synthetic and change it at 5K. 3K seems a little too soon to change Mobil 1.
Go to the consumer rating at the top of the Aveo forum and see what others are saying with both manual and auto.
Realistically this is the mileage I expected. I generally assume the real world mileage is only about 75% of the EPA ratings.
Overall I am quite satisifed with the car so far
Otherwise my best guesses would be that either you have a hanging brake or a bad (temperature?) sensor or computer that is keeping your engine in open loop mode (open loop is the default operating mode your engine uses at start-up before it reaches normal operating conditions where it can compute fuel/timing settings to optimize engine power and economy.) Your mechanic is probably too lazy/busy to actually warm the car up and drive it with a scanner hooked up to see what's actually going on. If he hasn't done that IMHO he hasn't done his job.
I am guessing that you need to find a different mechanic/dealer--one who knows something about cars.
We are getting mid 30's around town and low 40's on the highway out of our Aveo.