I'm impressed with my car's mpg calculation

[wbwanzer]

My '23 Hyundai Santa Fe's onboard gas mileage is impressively accurate. For comparison, the Kia Sorento that I had previously and my wife's Kia Seltos were/are consistently overstated by 10%. If the car said 30 mpg it was really more like 27. My current Santa Fe's calculations are accurate or more often understated. I always fill up and print a receipt which of course shows how many gallons I purchased. I write on the receipt how many miles were traveled and what the car had calculated as my mpg during those miles. I throw the receipts in the center console and then periodically enter them into Fuelly. Just the other day I entered nine receipts worth of fill ups into Fuelly. Seven out of the nine receipts showed that the actual mileage calculated by Fuelly was higher than what the car had calculated. And it's not unusual for the majority of the actual mileages to exceed what the car had calculated. I'm impressed with the cars tendency to actually understate the gas mileage. I'm not used to that.

 

[RhondaHonda]

You bought it new? That’s pretty good. On the F-150s I could tweak the calculation to get it closer based on actual numbers to make the computer more accurate. I’d imagine other brands allow something similar.

 

[fantastic]

Is this the time I tell you to "toot your own horn" Really go out & honk your Kia horn a couple of times.
I guess some vehicles do it better than others & happy to hear your experience. Fuelly is my go to mileage & cost tracker as well.

 

[wbwanzer]

Yes, bought new. I haven't tweaked anything. Wouldn't know how.

 

[Klutch9]

Our Carnival is also overly optimistic. Took a trip out east last month and the screen showed just over 30 mpg average. Hand-calculated, it was just over 28. Still really good for what it is, but not accurate haha.

 

[Kira]

I always fill up and print a receipt which of course shows how many gallons I purchased. I write on the receipt how many miles were traveled and what the car had calculated as my mpg during those miles. I throw the receipts in the center console and then periodically enter them into Fuelly. Just the other day I entered nine receipts worth of fill ups into Fuelly. Seven out of the nine receipts showed that the actual mileage calculated by Fuelly was higher than what the car had calculated. And it's not unusual for the majority of the actual mileages to exceed what the car had calculated.

SUGGESTION:
Try using just 4 columns in a notebook. You hand calculate anyway?
Date........Odometer......Volume (gallons).......Cost ($)
Tally monthly.

IRONY:
Today's cars can precisely measure airflow, fuel delivery and fluctuations in gas content in the exhaust stream.
Yet, the mpg metering is consistently inaccurate all over the industry.

 

[Al]

My Mazda CX-30 is also accurate.

 

[14Accent]

My '95 Seville is impressively accurate with both it's MPG and gallons used readout. I reset both at each fill: MPG is within a couple tenths of hand math as is gallons used.

 

[Propflux01]

My 2024 Mazda CX-5 is dead on accurate.

 

[AZjeff]

Anything I’ve owned that calculated mpg was/is optimistic by 1-3 mpg. This HD truck is closer when it’s working harder towing.