Mass Airflow Sensors - MPG

[AVC]

And Black smoke does not always ,mean high HC's and CO's which would be a emission related and EPA regulated exhaust.

Well, black exhaust (oily or sooty) ALWAYS indicates unburnt hydrocarbons (the EPA considers emissions), even for the mysterious (that only Tribe understands) SkyActiv. The EPA standard is stated as xx% of noxious gases and xx% particulate matter, per mile driven. For a vehicle to be EPA compliant in its declared bin (and contribute to fleet avg bin) it has to spend the vast majority of a drive cycle in closed loop and not straying from stoich very far and not very often. You can burn as much fuel as you like (large displacement, high compression, turbo or super charging), but it has to remain near stoich for most of the drive cycle.

Last, on my CX-5, I've played with one factory and two OEM fresh MAF sensors, and they all differ slightly in calibration which can be measured and felt in low speed drivability. Not dramatic, but it is real. Mazda chose hot-film sensors for response speed (presumably), but these sensors are more difficult to manufacture to tight tolerances (as compared to many vehicles that use hot-wire). I noticed that in 2018 or 2019, Mazda switched MAF suppliers. Don't know why, but maybe the new supplier has better product consistency.

 

[acidbug]

Another thought I had was trying to clean the existing MAF with MAF cleaner and see if it helps.

A lot of people don’t realize that manufactures read these forums.

Also, Honda engineering would change it to add extra mpg as long as it wouldn’t hurt the longevity of the motor. Even Mazda added cylinder deactivation to get that extra 1 mile per gallon which tells you how desperate they are to get the most mpg.

It’s not like back in the day where MPG wasn’t a big deal. Today most people are very concerned with the ICE MPG compared to hybrids easily beating ICE cars.

 

[Tribe&TrueRacin]

Another thought I had was trying to clean the existing MAF with MAF cleaner and see if it helps.

A lot of people don’t realize that manufactures read these forums.

I am only asking but where did you get that information?
As there are hundreds maybe a few thousand automotive related forums and most are basically DIY members why would any auto manufacture unless it was simply an individual that was curious ever want to come to a forum and read all this DIY information? Even aftermarket manufacture OE and performance seldom if ever come to forums except to promote or advertise a product?


I do support that frequent cleaning of inductive system sensors is very beneficial especially with DI (direct injection) engines because of the high possibility of oil film accumulation on the reporting part of sensors.

 

[Odrapnew]

Anyone have any links to these sites where they report improved MPG with mass air meter change?

Also, if a company could safely increase MPG by ~15% (assuming 5mpg added to 34 mpg rated highway) without impacting power, wouldn't you think they'd implement it?

 

[Silly Wabbit]

Also, if a company could safely increase MPG by ~15% (assuming 5mpg added to 34 mpg rated highway) without impacting power, wouldn't you think they'd implement it?

Emission regulation? But chances are very slim.
I think this thread has reached it's conclusion already.

 

[ColtX-5]

....

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.

Best power mixture for gasoline is 13.2:1 for most engines. More is only used when cooling is required as in a supercharged engine.
To meet air emissions the Stoichiometric ratio of 14.7 is used as it is the intersection of falling hydrocarbon and rising NOx emissions and usually provides enough excess O2 for the catalytic converter to work.
Best Economy Mixture is 16 to 18 to 1, depending on the combustion chamber shape and compression ratio (higher comp ratio can usually run leaner before lean misfire), but that lean causes enormous NOx production which has become verboten.

My CX-5 runs at 14.7 until almost wide open. I haven't looked at WOT. If yours is running 11:1 or less, you have a bad malfunction.