I have been investigating a future purchase of a 2022 or newer Honda Civic. I have been reading online reviews featuring issues with vehicles not average close the maximum EPA averages. What issues would cause the car not to receive the normal gas mileage? Some of the vehicles have been driven 2,500 or miles. Any input is appreciated.
The EPA mpg ratings are achieved in perfect conditions. In other words these ratings are measured under controlled conditions in laboratories so it's basically impossible for those same conditions to happen in daily driving. The numbers won't be off by for example 10 mpg but you shouldn't expect those exact numbers either.
https://www.fueleconomy.gov/feg/how_tested.shtml
EPA mpg ratings are a lie.
EPA testing isn’t exactly real world conditions. With that said, it is an ok proxy to understand the differences between MPG of one vehicle vs MPG of another vehicle. While you won’t usually get those MPG’s, a higher MPG rating is usually a better gas mileage car IRL, and a lower MPG rating is usually worse gas mileage IRL.