~40.75 mpg In my Elantra
 

Finally surpassed the 40 mpg mark for my 2012 Hyundai elantra. 380 mile round trip to Mathis Texas back to Austin. I even went through downtown Austin in rush hour and still managed to keep the tank above 40. My best previous trip was ~39 mpg. I felt like I could have pulled off a higher number had I not hit 5 lights at the end of the trip. No EOC at the light because it was 90+ outside and my girlfriend mandated the use of A/C.

Possible reasons for the increase.

1. I kept the car at an average speed of about 62-63 mph.
2. I added a revised underbody pannel from the rear axel back after my last trip south.
3. I may have had a favorable tail wind on the return trip.

Grats!

Cool beans. What tire inflation pressure do you use? We drove my wife's 2012 AT Elantra to California from Louisiana. 900 miles at the speed limit got us 34.2 mpg. One 404 mile tank at 60 mph got 38.4 mpg. Then I inflated the tires to max. sidewall pressure, kept the speed @ 60 mph, and we averaged 44.7 mpg for the next 1100 miles.

I have kept my tires at 40-to 42 psi since August of last year. I didn't see much change but I know it can hurt. 44.7 is a great return. I can image that I would have done better if I could have made the whole trip at 60. I felt like I at least had to maintain 65mph durring the 75mph speed limit sections. Most of the traffic was already not happy with me since they were doing about 80mph.

On a second note my 90 day average is finally above the epa's combined number of 32mpg. I can definatley see that my changes to the car, my driving style and some route planning have made an impact on my fuel consumption over last year around this time. Limiting the use of the A/C has aslo helped a little. Although, not on this last trip.

New best tank was 42.98mpg same route as before. The only change was the addition of a front upper grill block. Then today I had a record trip of 49.5mpg on the way home from the store. I can only imagine what I could do if I could Eoc.

Why can't you EOC?

Its not good to EOC if you have an automatic transmission.

Keeping the TC locked, speed down, no stops or hills, & the AT in 6th gear, are the keys. I could probably approach 55-60 mpg on a road where I could drive @ 45-50 mph all day.

My 2013 auto Elantra real-world steady-states around 51mpg in 6th gear, about 49mpg in 5th gear & 48mpg in 4th gear, using 100% gasoline(ethanol-free). If a driver is even slightly impatient however, Elantra's low 131 lbs-feet of torque, makes mpg go away quickly, thus all the complaints about Elantra mpg giving somewhat less than EPA ratings.

Presently, my Elantra is averaging 39mpg(last 5 of 6 tanks have been 40mpg or more) with city driving being 15% & tanks used up in 4-7 plus days.

For yours, or do you just mean in general? It could be more involved, depending on how one looks at it, but depending on the drive, it could be worth it. There are some cars that it should NOT be done on, I was just curious.