FYI: really substantial gas mileage increase

This is difficult to believe. If mileage could be improved this much surely Hyundai would be taking advantage. How many miles did you drive? Have you validated the number by dividing number of miles traveled divided by number of gallons added? Seems most likely you benefited from a tailwind.

Doubtful.


Also, you can't gauge a fuel mileage increase off of one single instance. And the things jetrep mentioned above. You'll need to make multiple trips, fuel logging, and you'll also need to take the SAME trips repeatedly to get a mean and an average. You'll also need to record weather conditions for the day.



I can probably get 41MPG in my N-Line, if it's a calm day, flat land, use a light touch on acceleration, and keep it under 50MPH. I was able to get 52MPG in my 2017 Elantra Value Edition sedan (rated 39MPG highway) once, but in that instance I DID have a tailwind, and I was doing between 45 and 55MPH with the air conditioner off.

as mentioned, the mpg was recorded on a 10 mile trip, 2/3 highway and 1/3 town driving. it will probably come down over time, but I thought it deserved comment because the mpg was SUBSTANTIALLY improved. it was only a day ago, and, sure, I understand that for a technical analysis, I'd need to do technical testing with technical parameters........that wasn't the point......it shocked me that there was an improvement at all, let alone an improvement of this magnitude!

rpnuy said:

as mentioned, the mpg was recorded on a 10 mile trip, 2/3 highway and 1/3 town driving. it will probably come down over time, but I thought it deserved comment because the mpg was SUBSTANTIALLY improved. it was only a day ago, and, sure, I understand that for a technical analysis, I'd need to do technical testing with technical parameters........that wasn't the point......it shocked me that there was an improvement at all, let alone an improvement of this magnitude!

Click to expand...

You did not mention the trip was 10 miles in the original post. Ten miles is nothing and the reported 41mpg is totally meaningless...sorry. I suspect you'll find zero improvement in fuel economy.

thanks for the thoughts. the mileage is remaining way higher than it was before the new muffler. yes, I know that more time will be needed to make a definitive statement......BUT I remain impressed with the magnitude of the positive change in mpg..........and THAT was the point

It's a great car, and definitely enjoy it. Just don't use a single data point of a common modification, to try and disprove a scientifically tested and proven EPA rating.

It is most likely because of the sudden increase in exhaust noise, you were lighter on the acceleration pedal.

Btw, may I ask how much the total cost for parts and labor was, for the muffler install?
(Would love to hear it in a video clip!)