Consumer Watchdog has been highly critical of the gap between the Hyundai Elantra's posted 29 city/40 highway MPG numbers and reality. We've asked the Environmental Protection Agency to re-test the Elantra, because even the most eco-aware drivers say they can't reach those numbers, or the company's 33MPG combined MPG.

Hyundai has responded that only people who "drive like maniacs" can't equal the posted MPG, but here's a complaint from the opposite of a maniac driver. Marc, an East Coast driver, told us:

I read your articles on the Hyundai Elantra with great interest.  While I really like the [Elantra], I have consistently had the same experience as you noted regarding gas mileage.  My combined mileage has never exceeded 29 and is usually between 26 and 28, my city mileage is in the low 20's and highway mileage in the low 30's at best.  What makes all of this troubling are two factors.

First, I always drive in ECO mode and I drive with the goal of keeping the green eco light on all the time.

Second, I rarely drive in city rush hour traffic, rather most of my city, really suburban,  driving is in light suburban traffic, and it is a rare trip where I ever wait more than one light cycle to get through an intersection and travel speeds are typically between 35 and 45 mph.  On the highway, I am usually in free flow, though 2-3 miles of my daily commute may be as low as 30-35 mph on some days – otherwise it's 55.  I typically drive between 55-65 and don't exceed that top speed with any regularity.  I recently returned from a 180 mile highway trip, using cruise control from 60-65 and my mileage was 33.7.  I've driven extremely steady highway trips of 40 miles and it's always between 34 and 37.

So I've never seen the advertised mileage, no matter how carefully I drive.  It's very frustrating because the city mileage is barely better than what I was getting on the Audi A4 I traded in so I could get a high mileage vehicle.

People who don't drive like Marc obviously get even worse mileage. Hyundai says that other cars also don't meet their listed MPG in real-world tests, but our analysis of independent tests shows that the Elantra is at the bottom of the heap. And that is what we wrote Wednesday in a letter to Hyundai's U.S. CEO. If even the most careful and light-footed driver can't get to the listed MPG, Hyundai is deceiving the very people who its advertising targets.