i recently purchased an off-lease (previous rental) 2004 alero 2.2L with auto trans. i got 26 mpg for the first tank of approximately 75% highway driving. i got 30 mpg on the second tank which was almost entirely interstate driving at 65-70 mph. during both tank fulls i drove very conservatively (no fast starts or stops, excessive speed, etc.)
the epa highway estimate for the 2.2L Alero is 33 mpg which at a first glimpse makes it seem like my alero isn't performing quite as well as expected. but once you consider how the epa actually tests mileage, it is easy to see the vehicle is performing fine. first of all, colder winter temps and oxygenated and reformulated fuels, which reduce fuel economy, are not considered in the epa testing. they use a lab temp of 68-86F and are not using the vehicle's air conditioning at all. and notably, the profiles they drive on their dynamometer have a maximum city speed of 56 mph but use a maximum highway speed of only 60 mph!
check out the actual profiles:
http://www.fueleconomy.gov/feg/fe_test_schedules.shtml
at 70 mph on the highway, it becomes very difficult to get the epa estimated fuel economy since the government's testing was conducted at an average of only 48 mph. and in the city, it seems like most traffic lights last about two minutes. the epa profile's stops are much shorter and some of the time moving between stops is approximately 3 minutes (try doing that in your nearest city).
it seems like many people today are complaining about poor gas mileage. i think it is in part because how the epa conducts its tests is not well understood. those with hybrid vehicles are complaining the most since the hybrids are not coming anywhere close to the epa estimates in the real world. one reason is that hybrid engines typically have to run when the ac is on with the vehicle stopped.
02-14-2005, 02:09 PM
Fuel Economy OK
