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Thymeclock · 01-02-2010, 05:35 PM

I’m beginning this thread to discuss every viable idea to improve FE on the Aveo.

We have a new 2009 Aveo 5 with automatic transmission that my wife uses for her daily commute to work. (She loves the car and we really don’t regret having bought it.) The type of driving we do with it is all ‘city’ (local streets with a stop sign on almost every corner and between 0-40 mph on major streets). We are only getting 22 mpg. The EPA estimate for city driving was originally 27 MPG, but eventually that figure was restated to be 25. For a car this small the city MPG is disappointing. I’m determined to try to raise the FE by at least a few MPG to the EPA estimate. I found the body of the car to be very similar to the Toyota Yaris, which I also drove before buying. But apparently similar models of competitors (Yaris, Honda Fit, and Kia Rio) all get better city MPG, if the EPA figures are to be believed.

Why does this car get such inadequate FE in city driving? Personally, I think it might be a combination of things. I’ve tried to list everything I could think of that might be a factor:

Weight
Aerodynamics
Transmission design
Engine control electronics

Comparisons with similar sized cars (all with A/T):

Aveo: 25 City / 34 Hwy.
Fit: 28 City / 35 Hwy.
Yaris: 29 City / 35 Hwy.
Rio: 25 City / 35 Hwy.

Aveo: 2557 lbs. 1.6 liter engine 4 speed
Fit: 2489 lbs. 1.5 liter engine 5 speed
Yaris: 2293 lbs. 1.5 liter engine 4 speed (plus overdrive?)
Rio: 2438 lbs. 1.6 liter engine 4 speed

Aveo ground clearance: 7.5 inches
Fit ground clearance: 6.5 inches (looks even less in front)
Yaris ground clearance: 5.5 inches
Rio ground clearance: 6.1 inches

An Aveo is about 250 pounds heavier than a Yaris, which also has a slightly smaller engine. The Aveo sits at least an inch higher off the ground than all the others. This makes it an easier car to get in and out of, and it’s better suited to clear low driveways and city streets that have dips and bumps without bottoming out. Considering our car is being used almost exclusively for city driving, that’s desirable; but possibly it is a disadvantage in the aerodynamic design. Also it is a VERY ‘tall’ car – to the extent that it’s difficult to reach the center of the roof when washing it.

Aerodynamically, there is virtually no air deflector at all under the front bumper of an Aveo. It’s just a huge, open space. The grille is similar in style to other much larger Chevy vehicles (in an attempt to make this small car look bigger?) in that it has a huge grille, again with much open space. To modify this I made an air deflector that now covers the vast area between the front bumper and its trailing edge where the wheel wells begin. Fortunately this can be done without obstructing anything related to routine service work. I also designed a lower grille block that is invisible, mounted behind the grille, and an upper grille block that is mounted externally and easily removable. (See it here) I happened to see a Honda Fit on the street and looked underneath the front end of it – it has the similar underside area covered by panels.

I doubt there is anything that can be done with the Aveo’s engine or transmission to improve FE. Ironically, the car has decent acceleration from a standstill (thanks to it being marketed toward American tastes and desires for power). Few Americans would buy one if it couldn’t get out of its own way. But I think that is a factor affecting fuel consumption. The Yaris and the Fit apparently both have more sophisticated transmissions, and that may be the primary reason for their superior FE. Apparently the Aveo is most similar to the Kia Rio in comparison, which is (maybe not coincidentally) also of Korean manufacture.

Now that it has about 1000 miles on it, I recently bought a ScanGauge in hopes of lightening my wife’s foot on the gas pedal. Time will tell, and I hope to see some improvement, however slight. I would welcome hearing from all other Aveo owners about their experiences and interests in mods that might help. Also, if anyone has one of the other brand models mentioned with A/T and does city driving primarily, I’d like to know whether all the EPA ratings are all inflated.

01-02-2010, 05:35 PM	#1 (permalink)
Thymeclock Banned Join Date: Dec 2009 Location: NY Posts: 865 Thanks: 29 Thanked 111 Times in 83 Posts	Chevy Aveo: How to improve CITY MPG? I’m beginning this thread to discuss every viable idea to improve FE on the Aveo. We have a new 2009 Aveo 5 with automatic transmission that my wife uses for her daily commute to work. (She loves the car and we really don’t regret having bought it.) The type of driving we do with it is all ‘city’ (local streets with a stop sign on almost every corner and between 0-40 mph on major streets). We are only getting 22 mpg. The EPA estimate for city driving was originally 27 MPG, but eventually that figure was restated to be 25. For a car this small the city MPG is disappointing. I’m determined to try to raise the FE by at least a few MPG to the EPA estimate. I found the body of the car to be very similar to the Toyota Yaris, which I also drove before buying. But apparently similar models of competitors (Yaris, Honda Fit, and Kia Rio) all get better city MPG, if the EPA figures are to be believed. Why does this car get such inadequate FE in city driving? Personally, I think it might be a combination of things. I’ve tried to list everything I could think of that might be a factor: Weight Aerodynamics Transmission design Engine control electronics Comparisons with similar sized cars (all with A/T): Aveo: 25 City / 34 Hwy. Fit: 28 City / 35 Hwy. Yaris: 29 City / 35 Hwy. Rio: 25 City / 35 Hwy. Aveo: 2557 lbs. 1.6 liter engine 4 speed Fit: 2489 lbs. 1.5 liter engine 5 speed Yaris: 2293 lbs. 1.5 liter engine 4 speed (plus overdrive?) Rio: 2438 lbs. 1.6 liter engine 4 speed Aveo ground clearance: 7.5 inches Fit ground clearance: 6.5 inches (looks even less in front) Yaris ground clearance: 5.5 inches Rio ground clearance: 6.1 inches An Aveo is about 250 pounds heavier than a Yaris, which also has a slightly smaller engine. The Aveo sits at least an inch higher off the ground than all the others. This makes it an easier car to get in and out of, and it’s better suited to clear low driveways and city streets that have dips and bumps without bottoming out. Considering our car is being used almost exclusively for city driving, that’s desirable; but possibly it is a disadvantage in the aerodynamic design. Also it is a VERY ‘tall’ car – to the extent that it’s difficult to reach the center of the roof when washing it. Aerodynamically, there is virtually no air deflector at all under the front bumper of an Aveo. It’s just a huge, open space. The grille is similar in style to other much larger Chevy vehicles (in an attempt to make this small car look bigger?) in that it has a huge grille, again with much open space. To modify this I made an air deflector that now covers the vast area between the front bumper and its trailing edge where the wheel wells begin. Fortunately this can be done without obstructing anything related to routine service work. I also designed a lower grille block that is invisible, mounted behind the grille, and an upper grille block that is mounted externally and easily removable. (See it here) I happened to see a Honda Fit on the street and looked underneath the front end of it – it has the similar underside area covered by panels. I doubt there is anything that can be done with the Aveo’s engine or transmission to improve FE. Ironically, the car has decent acceleration from a standstill (thanks to it being marketed toward American tastes and desires for power). Few Americans would buy one if it couldn’t get out of its own way. But I think that is a factor affecting fuel consumption. The Yaris and the Fit apparently both have more sophisticated transmissions, and that may be the primary reason for their superior FE. Apparently the Aveo is most similar to the Kia Rio in comparison, which is (maybe not coincidentally) also of Korean manufacture. Now that it has about 1000 miles on it, I recently bought a ScanGauge in hopes of lightening my wife’s foot on the gas pedal. Time will tell, and I hope to see some improvement, however slight. I would welcome hearing from all other Aveo owners about their experiences and interests in mods that might help. Also, if anyone has one of the other brand models mentioned with A/T and does city driving primarily, I’d like to know whether all the EPA ratings are all inflated. Attached Thumbnails