She drives like a turtle, and when I drive, people are always going around me as well, but I drive the speed limit, I just don't rush light to light. Anyway, the Sonic has NEVER got more than 28mpg under any circumstance. I took the car back to the dealership, they took it in, and later that day returned it and said NOTHING was wrong, and they could not do anything because nothing was wrong. My 1999 chevy tracker gets 25-27, is a 4x4 and basically a rolling brick.
I know there are a ton of factors in determining the MPG, I was not expecting 40, but at least give me a good 34-39, heck, even 32. I know that doesn't sound like much of a difference in MPG but over the life of the car, thats thousands of miles not including the gas "savings"
There are more things that are not right on this car, but as usual, no one really cares after the sale.
This Sonic is just bad, and no one seems to care. (because nothing is wrong)
lnbcab,
The fuel economy estimates are based on results of tests required by the U.S. Environmental Protection Agency (EPA). These tests are used to certify that vehicles meet the federal emissions and fuel economy standards. Manufacturers test pre-production prototypes of the new vehicle models and submit the test results to EPA. EPA re-tests about 10% of vehicle models to confirm the manufacturer's results. The vehicles are driven by a professional driver under controlled laboratory conditions, on an instrument similar to a treadmill. These procedures ensure that each vehicle is tested under identical conditions; therefore, the results can be compared with confidence.
There are two different fuel economy estimates for each vehicle in the fuel economy guide, one for city driving and one for highway driving. To generate these two estimates, separate tests are used to represent typical everyday driving in both a city and a rural setting. Two kinds of engine starts are used: the cold start, which is similar to starting a car in the morning after it has been parked all night; and, the hot start, similar to restarting a vehicle after it has been warmed up, driven, and stopped for a short time. Even though the EPA has improved its methods for estimating fuel economy, your mileage will still vary. There are several factors that can affect the miles per gallon significantly. Note: the EPA tests are designed to reflect "typical" driving conditions and driver behavior.
You can learn more about these factors on the link below:
Many Factors Affect MPG
These factors, as well as others, are listed below. Please educate the customer about how each of these factors can affect their gas mileage.
Quick acceleration and heavy braking can reduce fuel economy by up to 33 percent on the highway and 5 percent around town. New EPA tests account for faster acceleration rates, but vigorous driving can still lower MPG.
Frequent accelerator pedal movement will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (tcc) also disengages, contributing to fuel economy losses.
Excessive idling decreases MPG. The EPA city test includes idling, but more idling will lower MPG.
Driving at higher speeds increases aerodynamic drag (wind resistance), reducing fuel economy. The new EPA tests account for aerodynamic drag up to highway speeds of 80 mph, but some drivers exceed this speed.
Cold weather and frequent short trips can reduce fuel economy, since your engine doesn't operate efficiently until it is warmed up. In colder weather, it takes longer for your engine to warm, and on short trips, your vehicle operates a smaller percentage of time at the desired temperature. Note: Letting your car idle to warm-up doesn't help your fuel economy, it actually uses more fuel and creates more pollution.
Cargo or cargo racks on top of your vehicle (e.g., cargo boxes, canoes, etc.) increase aerodynamic drag and lower fuel economy. Thus, hang-on luggage carriers, cat toppers, open windows and/or open trunk, etc results in less fuel economy. MPG tests do not account for this type of cargo.
Towing a trailer or carrying excessive weight decreases fuel economy. Vehicles are assumed to carry only three hundred pounds of passengers and cargo during testing. Each 125 lbs. of additional weight results in a .3 mpg loss of fuel economy. Thus, additional passengers, luggage, etc will decrease fuel economy.
Running electrical accessories (e.g., air conditioner) decreases fuel economy. Operating the air conditioner on "Max" can reduce MPG by roughly 5-25% compared to not using it. Electrical loads, (headlights, heated back glass...) also result in lower fuel economy, (typically less than 1 mpg difference, each 10 amps takes approximately .4 mpg).
Driving on hilly or mountainous terrain or on unpaved roads can reduce fuel economy. The EPA test assumes vehicles operate on flat ground.
Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual imperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy.
A poorly tuned engine burns more fuel.
Improperly aligned or inflated tires can lower fuel economy by increasing rolling resistance. Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride.
A dirty air filter can make your engine work harder.
Brake drag (even a minimal amount undetectable by coasting) can have a significant negative impact on fuel economy.
Vehicle suspension misalignment can cause poor fuel economy, new tires, tire rotation, and/or front end alignment may be required to correct fuel economy.
Fuels vary in energy content: A vehicle's fuel economy depends on the energy content of the fuel on which it runs-this has been determined by EPA and others and is consistent with combustion theory. The use of oxygenated fuels or reformulated gasoline (RFG), for example, can cause a small decrease (1-3%) in fuel economy. In addition, the energy content of gasoline varies from season to season. Typical summer conventional gasoline contains about 1.7% more energy than typical winter conventional gasoline.
Vanessa
GM Customer Service
