Increased MPG

Jordo!

If one of the factors that affects target AFR is IAT's then that would certainly be true.

I think it gets confusing in part because power and MPG are kind of unrelated issues when you get down to it.

You could coast downhill consuming very little fuel and engine power, and improve MPG, or you could destroy a new set of tires with a smoky burn out, consume tons of fuel and produce lots of power (or, well, torque more precisely), go nowhere, and have terrible MPG.

Fuel consumption comes into play on the basis of fuel consumed to make so much torque over a period of time, but it doesn't necessarily translate into distance traveled.

That's why gearing and drag (either in terms of tire inflation, weight, or the ability to deflect wind) all wind up being such surprisingly important factors in MPG (those little plastic wind deflectors in front of the front tires come to mind...).

That's also why city MPG is always lower than highway MPG; taking off from a dead stop (i.e., stop and go driving) requires more energy than rolling along with the help of inertia.

I don't know about heat losses related to airflow, but losses as heat matter definitely in some aspects of MPG. A fluid coupling trans, for example, will lose power in the form of heat, and therefore have a poorer MPG than a solid connection to the driveshaft operating under the same conditions (although gearing and time spent in a given gear will affect MPG too).

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SouthArk370Z

The IAT is located in the MAF and used by the MAF circuit as part of the density calculations. Details are in the FSM.

Good explanation.

Any effect on MPG/efficiency due to cooling from airflow is pretty insignificant. Keep in mind that the air is "cold" only until the piston starts up.

Any heat loss means less efficiency. The "perfect" engine wouldn't have a radiator (and the drive wheel would be bolted to the crank). Some of the hyper-milers run their engines very hot, but that will lead to detonation problems (plus increased wear) for a "normal" driver.

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SlowRollin

Sounds like I need to lighten my foot a bit and enjoy the ride, thanks guys!

SouthArk370Z

Fixed

Edit: There was a real-time MPG monitor in my '09 Touring; if you have that, you may find it helpful. Or get an app for monitoring different variables. Also check out some of the hyper-miling sites. I doubt if anyone here would go to the extremes that they do, but there is still a lot of good info.

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Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

dmhenderson

I can say with some certainty that a supercharger and upgraded injectors/fuel pump do not help your gas mileage so you can cross those off the list.


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SlowRollin

How about this.... HFC and CBE. Better flow but no change to the air/fuel mixture. Nice performance increase too? Of course, Fast Intentions seems like the winner for both parts.

Jordo!

Better flow (i.e., more air) + same mixture ratio = more power and poorer MPG. It will add fuel to maintain same AFR via fuel trims to target. The faster exhaust can escape, the more air can be sucked in, so same result whichever side you improve flow on.

On a related note, everyone will make less power and have better MPG in the summer and more power/worse MPG in the winter, all else being equal...

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SlowRollin

Oh well. I guess I'll just get a gas card with a discount and floor this motha.