Mazda & Honda seem to be more ON with their dash reading and the handheld or cell phone calc.
Actual vs. Real MPG
- Thread starter dja4260
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My Raptor is off by about 1-1.5 mpg which I think has a direct correlation to how much I remote start it. I don't think the computer accounts for the remote start idle time. I believe the mpg computer can be adjusted up or down using Forscan.
The MPG display of my Tucson consistently reads 7% higher than hand calculation.
I've checked on multiple tanks ranging from almost all city driving to highway trips.
I've checked on multiple tanks ranging from almost all city driving to highway trips.
Originally Posted by benjy
thought it was about EPA VS REAL mpgs, which can vary widely for many reasons as seen by some "discussions" or even legal issues where manufacturers #s are way higher. living in hilly + mountainous areas along with colder temps prolly have the biggest influence besides the "NUT" behind the wheel!!
There's been a disclaimer on the sticker since the EPA #s were required on the new car invoice. No legal issues as it's very clearly stated that the #s are for comparison only and of course "Your mileage may vary".
thought it was about EPA VS REAL mpgs, which can vary widely for many reasons as seen by some "discussions" or even legal issues where manufacturers #s are way higher. living in hilly + mountainous areas along with colder temps prolly have the biggest influence besides the "NUT" behind the wheel!!
There's been a disclaimer on the sticker since the EPA #s were required on the new car invoice. No legal issues as it's very clearly stated that the #s are for comparison only and of course "Your mileage may vary".
UPDATE.
Returned home and have two more fill ups to report.
Fill up #2- 266.3 miles, 36.4 on display, 33.28 actual.
Fill up #3- 295.2 miles, 34.2 on display, 32.9 actual.
Returned home and have two more fill ups to report.
Fill up #2- 266.3 miles, 36.4 on display, 33.28 actual.
Fill up #3- 295.2 miles, 34.2 on display, 32.9 actual.
Fuel is actually sold by weight, which is corrected into 'gallons' by the fuel pump using a look up table that is dependant on temperature.
This explains much of the discrepancy experienced.
There may also be differences in fuel pump pressure between a brand new fuel system and a worn in one further affecting calibration.
This explains much of the discrepancy experienced.
There may also be differences in fuel pump pressure between a brand new fuel system and a worn in one further affecting calibration.
Originally Posted by pitzel
Fuel is actually sold by weight, which is corrected into 'gallons' by the fuel pump using a look up table that is dependant on temperature.
This explains much of the discrepancy experienced.
There may also be differences in fuel pump pressure between a brand new fuel system and a worn in one further affecting calibration.
According to this company, who makes many of the fuel dispensers I've seen, it's measured in volume.
https://www.gilbarco.com/eu/blogs/dispenser-blog-atc
Fuel is actually sold by weight, which is corrected into 'gallons' by the fuel pump using a look up table that is dependant on temperature.
This explains much of the discrepancy experienced.
There may also be differences in fuel pump pressure between a brand new fuel system and a worn in one further affecting calibration.
According to this company, who makes many of the fuel dispensers I've seen, it's measured in volume.
https://www.gilbarco.com/eu/blogs/dispenser-blog-atc
I see some pretty wild swings that I think are exclusively due to weather.
One tank I'll get 18 city then the next week I'll get 15. Van is rated 17 city. 2009 Caravan 3.3. A cold week will def. make a dent in fuel economy.
One tank I'll get 18 city then the next week I'll get 15. Van is rated 17 city. 2009 Caravan 3.3. A cold week will def. make a dent in fuel economy.
Jeez, I guess I gotta get my geek-ness going.
Now all the sudden, I'm excited about running a few tanks in both cars to check the math versus stated readout.
I believe after both vehicles click off at the pump they take .3 to .5 more of a gallon to top off or 2nd click. That is my habit, so at least it should be fairly consistent.
.3 of a gallon more or .3 less takes my 20.27 mpg average to 19.95 or 20.62
Now all the sudden, I'm excited about running a few tanks in both cars to check the math versus stated readout.
I believe after both vehicles click off at the pump they take .3 to .5 more of a gallon to top off or 2nd click. That is my habit, so at least it should be fairly consistent.
.3 of a gallon more or .3 less takes my 20.27 mpg average to 19.95 or 20.62
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Actual vs real? I don't think there is a difference. They mean the same thing.
Regarding claimed vs. real fuel economy, I've only had one vehicle with a fuel economy gauge and it is optimistic. Claimed economy is 22 mpg and actual (real)
economy is 21 mpg. This is consistent over 5 years of tracking every tank of gas.
Regarding claimed vs. real fuel economy, I've only had one vehicle with a fuel economy gauge and it is optimistic. Claimed economy is 22 mpg and actual (real)
economy is 21 mpg. This is consistent over 5 years of tracking every tank of gas.
Originally Posted by DGXR
Actual vs real? I don't think there is a difference. They mean the same thing.
Regarding claimed vs. real fuel economy, I've only had one vehicle with a fuel economy gauge and it is optimistic. Claimed economy is 22 mpg and actual (real)
economy is 21 mpg. This is consistent over 5 years of tracking every tank of gas.
You're correct. I made a poor choice of words.
Actual vs real? I don't think there is a difference. They mean the same thing.
Regarding claimed vs. real fuel economy, I've only had one vehicle with a fuel economy gauge and it is optimistic. Claimed economy is 22 mpg and actual (real)
economy is 21 mpg. This is consistent over 5 years of tracking every tank of gas.
You're correct. I made a poor choice of words.
I never trust the factory computer readout on my '16 Versa and do hand calculations on every tank. The computer is usually anywhere from 4-6MPG optimistic. Most of my driving is 45-55MPH on rural 2 and 4 lane roads with probably 10-20% small town driving. In 10K miles and just over a year of driving this car I'm averaging 47.005MPG. Nearly every tank the computer is giving me a reading of 50-55MPG. It seems like the better mileage I get on a tank the more optimistic the computer is. My Versa has the CVT with an EPA rating of 31 city, 39 highway and 34 combined. In 43 years of driving I don't think I've owned a car that wouldn't beat EPA rating if it was driven right. Even during the winter months this winter my worst tank has been 44.75MPG. Worst tank I've had since I bought it in Feb. 2019 was the first tank I ran through it at 42.345MPG, best was last summer 51.167MPG.
I was talking to my dad the other day and he mentioned the mpg on their 05 Prius they've had since new.
It's always at or near 50 but he said the colder temps seem to do better.
I'm thinking with the winters they've had lately and lots of icy roads and snow means he drives at a speed more in the sweet spot at that 55 mph range where most vehicles are more efficient.
Safe and dry road conditions are more like 70 mph for him.
It's always at or near 50 but he said the colder temps seem to do better.
I'm thinking with the winters they've had lately and lots of icy roads and snow means he drives at a speed more in the sweet spot at that 55 mph range where most vehicles are more efficient.
Safe and dry road conditions are more like 70 mph for him.
I think the fuel pump cutoff as well as metering calibration is inferior to the computer in most vehicles.
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