Chevy Aveo: How to improve CITY MPG?

[Thymeclock]

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.

[RobertSmalls]

Here's a list of things that have a big impact on your city MPG, ranked from biggest to smallest.

driving style - very big in the city!
the weather
LRR tires
aerodynamics
weight reduction

I would set up a "trip MPG" X-Gauge on the ScanGauge to coach driving style, and look around the forum for driving tips.

Also ask yourself whether you really need rear seats, or rear floor mats. You could start deleting optional equipment, converting to manual steering, and removing the car's interior, but the wife probably won't appreciate that.

I've heard the Aveo delivers pretty disappointing MPG, and I guess you outlined why. Good luck with it, and if you drive well, I'm sure you'll be able to beat EPA during the summer.

[Lazarus]

I think the biggest thing to look into would be an engine block heater. On short city commutes the cold numbers kill you. Aerodynamics probably will not come into play much just do to the stop and go traffic that you mentioned. I would concentrate on getting the engine hot as quickly as possible.

Engine Block Heater
Grill Block
Front belly pan.
Tire pressures.

With an automatic it's critical to know your shift points and drive the speed that gives you the lowest rpm. That might not be the posted speed limit it might be a little ffaster or a little slower use the SG to see where it needs to be. Driving techniques are key for this environment. Both you and your wife study the 100+ driving tips to fine tune your technique.

Here's the garage listing at EM. They are respectable numbers. Just keep working on it.

Winter is a tough time for all.

[Thymeclock]

Originally Posted by RobertSmalls

Here's a list of things that have a big impact on your city MPG, ranked from biggest to smallest.

driving style - very big in the city!
the weather
LRR tires
aerodynamics
weight reduction

I would set up a "trip MPG" X-Gauge on the ScanGauge to coach driving style, and look around the forum for driving tips.

I will, but I've only had the scan gauge for one tank of gas, and I need to calibrate it on the next fill-up. I currently have it set for mpg and for throttle position reading. I expect that the throttle position reading is the best feedback to re-educate someone who has a heavy foot on the gas pedal.

Also ask yourself whether you really need rear seats, or rear floor mats. You could start deleting optional equipment, converting to manual steering, and removing the car's interior, but the wife probably won't appreciate that.

<LOL> She certainly wouldn't! She drives it about 98% of the time and it is a new car, so anything that would affect the look or function of it is out of the question. She didn't mind my adding the ScanGauge, but after 30 years of marriage, I don't want to press my luck!

[Thymeclock]

Originally Posted by Lazarus

I think the biggest thing to look into would be an engine block heater. On short city commutes the cold numbers kill you. Aerodynamics probably will not come into play much just do to the stop and go traffic that you mentioned. I would concentrate on getting the engine hot as quickly as possible.

Engine Block Heater
Grill Block
Front belly pan.
Tire pressures.

I'm already doing everything but the block heater. I thought of it, but it won't help too much in our specific situation. At least our cars are garaged while at home, which is usually a bit warmer than the outdoor temps in winter. Typically, if it is 20 outside it might be more like 30 in the garage. She routinely drives about 8 miles to work and then back home. The block heater would be unusable at her workplace, which means that 50% of its use would be negated. Besides, we pay the highest electric rates in the nation, so any possible saving in gasoline would be offset by consumption of electricity, meaning it would be a 'wash'. I've considered a full radiator block, but seeing that I have all the grilles blocked already, I don't want to overdo it. I have a full radiator block on the car that I drive ('89 Galant) but those blocking panels are easily removable.

The weather has been absolutely brutal here recently. Yesterday and today have been about 20 degrees with constant 50 mph winds, which is a horrible wind chill factor. We have all new windows and insulated siding on our home, but those high winds still suck the heat out of a house.

With an automatic it's critical to know your shift points and drive the speed that gives you the lowest rpm. That might not be the posted speed limit it might be a little ffaster or a little slower use the SG to see where it needs to be. Driving techniques are key for this environment. Both you and your wife study the 100+ driving tips to fine tune your technique.

I'm aware of that, but I don't know how to teach that to her. The first lesson is to try to lighten the heavy foot.

[Domman56]

try an upper grille block and also I'd use a big K&N cone filter in place of the stock airbox, should suck up more engine heat and make the car run a little more efficiently.

[MetroMPG]

Still selling K&N filters, eh?

For a warm air intake, you could save yourself a pile money by doing it yourself with some strategically routed dryer ducting from the stock air box to the warm underhood source of your choosing.

[Thymeclock]

Originally Posted by Domman56

try an upper grille block and also I'd use a big K&N cone filter in place of the stock airbox, should suck up more engine heat and make the car run a little more efficiently.

If you read my posts you'll see that I already have all the grilles blocked.

[Thymeclock]

Originally Posted by MetroMPG

Still selling K&N filters, eh?

For a warm air intake, you could save yourself a pile money by doing it yourself with some strategically routed dryer ducting from the stock air box to the warm underhood source of your choosing.

That will be my summer project. (It's too G*%@*# cold right now!). What I hope to do is remove and retain the original air box, and find a smaller air box in a junkyard that I can alter and experiment with.

[Domman56]

Originally Posted by MetroMPG

Still selling K&N filters, eh?

For a warm air intake, you could save yourself a pile money by doing it yourself with some strategically routed dryer ducting from the stock air box to the warm underhood source of your choosing.

Shoot use a big 'ol Spectre filter it'd probably work just the same and it's half the price at autozone
Doesn't neccesarily have to be a K&N i was just saying a Cone filter in general