Mass Airflow Sensors - MPG
- Thread starter Lbear
- Start date
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- Mazda CX-9 Signature
What exactly is the science behind it? Less air detected so less fuel being pumped and increase the mpg?
CarpeDiem
Under Pressure
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- Superstitions
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- 2021 CE Turbo
People too often do things because they think it might help….something. Most times it is a plecebo effect which may make things worse, not better. Be careful about what you read on internet forums, being a sheep is not always the smart thing to do. Mazdas are not Hondas, why would this “idea” even be transferable from one brand to another? Solution - save your money.
Lol. Quackery
Only 12 left, I better order soon. Wonder if they sell them by the case. Take that Big Oil, I'm fightin' back.
Obviously. I remember these from years ago. Surprised they are still around. If you want to see a lot of snake oil check out some things in the audiophile world.
I'm curious how changing MAF sensor would impact MPG any significant amount.
Going out on a limb, but I believe the CX5 uses a 'typical' closed loop feedback system in which it reads O2 sensors to adjust fuel ratio when it's up to operating temp. This under most part throttle conditions. All a different MAF would do is change the fuel trims. The handful of minutes before the engine is warm, it would use base tables, so a different MAF could impact that, but that's not for a long period of time unless you only drive a few miles.
Does anyone know if the CX5 uses narrow band or wide band O2 sensors?
Going out on a limb, but I believe the CX5 uses a 'typical' closed loop feedback system in which it reads O2 sensors to adjust fuel ratio when it's up to operating temp. This under most part throttle conditions. All a different MAF would do is change the fuel trims. The handful of minutes before the engine is warm, it would use base tables, so a different MAF could impact that, but that's not for a long period of time unless you only drive a few miles.
Does anyone know if the CX5 uses narrow band or wide band O2 sensors?
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- Mazda
The Unique Mazda Skyactiv engine Technology are very high compression engines. 13:01 US & other countries 14:01 compression ratio.
You don't change any input sensors suppling operation information to the ECU that regulate fueling. Nuff said!
You don't change any input sensors suppling operation information to the ECU that regulate fueling. Nuff said!
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- Mazda
They are H02 not 02 sensors and my last post applies regarding H02 as they are input sensors to the ECU.
The only time to should go outside the box when experimenting is not with swapping sensors but by changing calibration cells in the ECU or what's called EFI/ECU Performance Calibrating. Slang term for those experienced in doing this are "Tooners". The professionals are called ECU Perfromance Calibration Technicians.
The Honda CRV mass airflow sensor swap does seem to get around 5 mpg more. I personally know a CRV owner who saw the MPG increase on 2 different CRVs.
I don't think it's a gimmick. Just not sure how the sensor swap works and why doesn't Honda use it to get better MPG from the factory?
I don't think it's a gimmick. Just not sure how the sensor swap works and why doesn't Honda use it to get better MPG from the factory?
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- Mazda
It is a gimmick and in the long run could damage an engine.
If I connected a scan Tool to the diagnostic connector, I would see right away a discrepancy in the HO2 reporting values.
But seems this is a MAZDA forum and not a Honda forum and a Honda engine is nothing like a MAZDA Skyactiv engine not sure why we are comparing them having to do with the ECU operations?
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- ‘19 CX-5 GTR Tu
Manufacturers typically tune the car rich because they test the car in all different scenarios including freezing cold and extreme heat.
Typically, Only time people upgrade their MAF/Map sensor is when they have a larger turbo and to better read the air coming into the engine.
If anything I would just get a tuner. They allow you to safely lean out the a/f mixture which will increase power and mpg’s. Remember the point of GDI is to cool the cylinders (manufactures get away with higher compression ratio running regular gas) compared to port injection that doesn’t offer the same cooling effect which is why they typically run lower compression ratio.
Finally, as others mentioned if the replacement MAF sensor leans out the A/F and your not monitoring it, can lead to predetonation and early engine failure.
Typically, Only time people upgrade their MAF/Map sensor is when they have a larger turbo and to better read the air coming into the engine.
If anything I would just get a tuner. They allow you to safely lean out the a/f mixture which will increase power and mpg’s. Remember the point of GDI is to cool the cylinders (manufactures get away with higher compression ratio running regular gas) compared to port injection that doesn’t offer the same cooling effect which is why they typically run lower compression ratio.
Finally, as others mentioned if the replacement MAF sensor leans out the A/F and your not monitoring it, can lead to predetonation and early engine failure.
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- Mazda
Not sure where you saw that information about the test vehicles running different ECU maps for test. Most all Auto manufacture follow the CAFE under the USDOT for US and EURO market is very similar. So no "typically tune the car rich" for testing and posting required results. In the ECU world of engine richens not only effects all the drivability but will reais e the vary narrow of limits allowed in many country for exhaust emissions.
ECU calibration adjustments are becoming more for individuals and companies offering the service with some training and possibly certification to safely change maps in an ECU.
Going to larger Turbochargers over stock does not always mean the need to change sensors. This is always determined by the total boost targeted.
ECU calibration adjustments are becoming more for individuals and companies offering the service with some training and possibly certification to safely change maps in an ECU.
Going to larger Turbochargers over stock does not always mean the need to change sensors. This is always determined by the total boost targeted.
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- ‘19 CX-5 GTR Tu
What about what VW did with their diesel cars. Mercedes and a few others got caught tampering with those tests.
Also, during startup the car runs rich to get the cat’s warmed up faster for better overall emission.
Also, look at any turbo car that is GDI and factory tuned and you will see black soot all over the exhaust tips and bumpers. That soot is typically unburnt fuel.
Factory a/f for our cars are in the 10’s & 11’s. That very rich considering most tuners shoot for low 12’s A/F.
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- Mazda
The MAZDA mapping in the ECU for a Skyactiv engine is VERY different than any other platform currently available for the general public. And Black smoke does not always ,mean high HC's and CO's which would be a emission related and EPA regulated exhaust.
As for you generalized statement about AFR's that what they are generalized. Its not how the mapping works ultimately in the ECU but rather that it is target AFR for best overall performance with the least amount of emissions during throttle position that would be cruise to little load % . My thoughts would be to do a little research on EFI/ECU programing before assuming how you think they work? And then when you think you understand it all add a automatic transmission in the equations specifically the ones used in MAZDA Skyactriv engines and learn all over again what you just learned!
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- ‘19 CX-5 GTR Tu
I’ve owned more then 5 Mazdas in my life time from NA to turbo. this is my 1st auto turbo from Mazda. I’ve custom turbo’d/nitrous Mazdas from the protege to the speed6 & speed3. On NA motors they shoot for 14.7 a/f and any wideband will show the engine runs rich on startup. When chugging along the engine tries to hit 14.7 but will jump around a bit (especially if you have intake/exhaust mods) and when at WOT they run a closed looped system for max performance.
Going back to original thread I wouldn’t risk it unless it’s been tried and proven for at least one year. Also, some data logs at WOT making sure it’s not running 15’s A/F or retarding timing due to knock.
Going back to original thread I wouldn’t risk it unless it’s been tried and proven for at least one year. Also, some data logs at WOT making sure it’s not running 15’s A/F or retarding timing due to knock.
