That doesn't seem right...

"mkbruin, Atlas VP" (mkbruin)
08/08/2017 at 07:53 • Filed to: None

The Tundra doesn’t have a mpg display, so I loaded up my trusty Torque for Android to monitor my instant and average MPG.

not my display...

According to Torque, my 4.7l v8 commuter pickup averaged 28.3mpg. About 8-10mpg (50%) better than my former ‘09 Santa Fe v6.

I haven’t done a pump measurement yet, but I think Torque is optimistic by a factor of 2.

DISCUSSION (17)

LongbowMkII > mkbruin, Atlas VP
08/08/2017 at 08:01

Did it only roll downhill? Haha

Ash78, voting early and often > mkbruin, Atlas VP
08/08/2017 at 08:18

This is exactly how they tested the Prius for the EPA sticker.

Smallbear wants a modern Syclone, local Maple Leafs spammer > mkbruin, Atlas VP
08/08/2017 at 08:18

For the brief time I used Torque I found it to be total bogus.

MasterMario - Keeper of the V8s > Smallbear wants a modern Syclone, local Maple Leafs spammer
08/08/2017 at 08:26

In general? Or just for MPG? I have Torque, but I only really use it as a code reader, but I can see it being useful if there are things you’d like to monitor that don’t display on the dash.

MasterMario - Keeper of the V8s > mkbruin, Atlas VP
08/08/2017 at 08:28

https://torque-bhp.com/wiki/MPG

It’s probably assuming you’re engine is more efficient than it actually is, you can apparently adjust this in the app

Volumetric efficiency on most modern vehicles should be about 85%, though if you have a normally aspirated engine this could be as low as 75% (and on older late 1990's vehicles this could be down as far as 65%. Experiment with the VE figure first before using the ‘MPG adjustment factor’ as generally the MPG should be fairly close for your vehicle

Smallbear wants a modern Syclone, local Maple Leafs spammer > MasterMario - Keeper of the V8s
08/08/2017 at 08:31

MPG, power, acceleration. Code reader was good. The rest of the functions I don’t know about because I didn’t really mess with them, but fwiw I probably wouldn’t trust them after the numbers it spat out in the functions I did use. For a rough idea of what’s going on it’s fine I guess

In any case, for my purposes 1 out of 4 functions were good—so bogus.

bhtooefr > MasterMario - Keeper of the V8s
08/08/2017 at 08:41

Note that volumetric efficiency is referring to the amount of air that makes it into the cylinder, relative to cylinder displacement. It actually doesn’t have all that much to do with thermal efficiency (other than, Atkinson-cycle engines have intentionally low volumetric efficiency, to help improve thermal efficiency through reduced pumping losses past the throttle plate).

And, you can have over 100% volumetric efficiency in some cases.

However, my guess is that Torque is using “volumetric efficiency” as a skew on the mass airflow sensor data.

RallyDarkstrike - Fan of 2-cyl FIATs, Eastern Bloc & Kei cars > mkbruin, Atlas VP
08/08/2017 at 08:59

That is one weirdly steep roundabout :P

MasterMario - Keeper of the V8s > bhtooefr
08/08/2017 at 09:03

Yup, it’s been a while since I talked thermal or volumetric efficiency. I wasn’t really thinking when I typed that

Nothing > mkbruin, Atlas VP
08/08/2017 at 10:06

My ‘02, I probably averaged 12-13.

If only EssExTee could be so grossly incandescent > mkbruin, Atlas VP
08/08/2017 at 10:28

Your inclinometer also seems a bit off.

BLCKSTRM > mkbruin, Atlas VP
08/08/2017 at 11:52

Torque is great - except the MPG calculator. It bears no relationship to reality.

Said I was averaging 28 mpg pulling a loaded trailer in the loaded Escalade 1200 miles back from vacation. Nope, not even kind of close.

OK, a little close - it was a two-digit number.

TheD0k_2many toys 2little time > Smallbear wants a modern Syclone, local Maple Leafs spammer
08/08/2017 at 12:09

I mean its designed to be a code reader and to display anything that the OBD2 port puts out. The other stuff is just gimmick things that should be taken with a grain of salt. Power readings are only good from dynos and MPG even on OEM mileage calculations are usually off

Smallbear wants a modern Syclone, local Maple Leafs spammer > TheD0k_2many toys 2little time
08/08/2017 at 12:14

Technically, it’s all math. It should at least be able to get close.

For MPG, you’ve got your MAF data, engine size and RPM—should be able to get pretty close.

Power, you’re measuring the same thing a dyno does—rate of acceleration of a known mass. If you can get that number right you should get a pretty good ballpark figure.

TheD0k_2many toys 2little time > Smallbear wants a modern Syclone, local Maple Leafs spammer
08/08/2017 at 12:21

which torque makes you provide for all the calculations it does and often its easy to get the numbers slightly off which causes the result to be wrong.

Smallbear wants a modern Syclone, local Maple Leafs spammer > TheD0k_2many toys 2little time
08/08/2017 at 13:00

I had to provide the numbers for my UltraGauge, too... it’s numbers are right.

HammerheadFistpunch > mkbruin, Atlas VP
08/08/2017 at 22:34

make sure to go in and check the option for accurate mpg (may slow sensors) otherwise its garbage for mpg est. if you check it then its pretty close to reality. damn close.