Truck Trend claims 10% more MPG with K&N in 2009 Ford F-150 after bogus road test

[Domman56]

wouldn't it make LESS of a difference on the dyno because the truck is just rolling on the rollers and not really working to pull the truck along?

[Christ]

Do you know how a dyno works?

[Milwaukee]

[QUOTE=Frank Lee;132946]


They must have that data; after all the "article" is about fe???...

They do show air/fuel ratio (green bar at lower left corner)...



[Quote]

That interested and we try KN air filter on 2000 F250 V10 nothing change it SCAM.

And what that software isn't free version?

[Tweety]

You guy's are missing a big fat red sign here...

In ecomodding, better eairflow means better mileage... In engine tuning, better airflow deas NOT, I repeat, NOT equal better mileage... I'm a gearhead by nature and yes, I do have a flowbench and dyno out in the garage...

I can tell you from personal experience that getting better airflow in that K&N will decrease the mileage regardless of the other antics that rag pulled...

The computer will "solve" the problem by throwing more fuel in there to keep the car running the right mixture... More flow = more fuel = more power... Not mileage...

They can claim whatever they want... I'm not sold...

The reason why K&N does NOT claim better mileage is that the result of the K&N filter is more power, and since the driver will then 9 times out of 10 use that power that equals less mileage, even less than the actual change to the mileage had the usage remained the same...

[Christ]

Had the usage remained the same, no change would have taken place, my friend.

The engine will use only as much air and fuel as you tell it to, in a specific ratio, regardless of what it's pulling that air through. It doesn't care if there's a sock there, or a HEPA approved filtration unit. It will only pull through as much air as the power it's making, and power output is solely dependent on throttle angle and engine speed in our case.

[Tweety]

Well... My point exactly... We try for more milage... They don't...

And yes... there would be change... If the user would apply the same amount of throttle (same usage) with a better flowing filter, the computer would just as you say apply the same ratio fuel... Since they improve flow over stock it implies more fuel... Hence the less mileage on the same usage...

[Christ]

That would only work out if the OEM filter wasn't capable of flowing the amount of air necessary at a given throttle angle.

The engine, in our case, hardly ever requires more air than the OE filter can handle flowing, therefore there is no restriction. You can test this with a simple vacuum gauge on the intake pipe after the filter.

Since the K&N isn't flowing any more air than the OE filter was, due to the requirement for air not changing, there is no more fuel being injected, and thus, no change in economy or power.

Engines work on demand, not supply. If the engine isn't asking for more flow by increasing manifold vacuum, it's not getting any more. Period. Full Stop.

[Domman56]

Originally Posted by Christ

Do you know how a dyno works?

you strap your car to the dyno and do pulls to see how much power your car makes to the Drive wheels because there is a significant loss from the crankshaft to the actual rear wheels. Variables on a dyno would usually be whether you had a fan infront of the intake or not as well as tempurature Air fuel ratio ect.

[mcrews]

Two thoughts:
1.) Frank Lee....did you take into consideration that the graph paper wasnt lined up in the printer!!!!!????!?!?!?!?!? huh!!!!!!
(oh....gragh prints at same time.........sheeezzzzzz)

2.) Don't you just love it when Frank Lee gets his dander in an uproar....!!!!!!

[Christ]

Originally Posted by Domman56

wouldn't it make LESS of a difference on the dyno because the truck is just rolling on the rollers and not really working to pull the truck along?

Originally Posted by Domman56

you strap your car to the dyno and do pulls to see how much power your car makes to the Drive wheels because there is a significant loss from the crankshaft to the actual rear wheels. Variables on a dyno would usually be whether you had a fan infront of the intake or not as well as tempurature Air fuel ratio ect.

You can't determine HP ratings or Torque output without loading sufficient to create that output. Therefore, the truck (vehicle) is absolutely not just rolling on the rollers, as you put it. The engine is stressing just as hard, if not harder, on a dyno environment, than it would be in the real world on a normal street.

The Dyno is considered controlled conditions, and thus, is able to be used for scientific testing moreso than driving the vehicle in the open. More variables can be controlled using the dyno, and in some cases, fuel input can be logged directly and compared to HP output to determine things like peak efficiency, BSFC maps, BMEP maps, peak torque output, and more.

I'm not sure where you got the idea that it's just "rolling on the rollers", and I don't want to know... but it's just not the way it works.

I've made runs on a dyno in several types of vehicles. Particularly of note, and something I didnt' know until recently, is that turbo cars require a different type of run to get an accurate reading, because the dyno doesn't load the engine properly to spool the turbo. You rev the engine up to enough speed to get into 3rd/4th gear (doesn't actually matter what gear you're in, but you want to load the engine for an accurate reading, and not take all day doing it), then the dyno loads the engine up enough to surpass it's power output and drag it back down to a decent engine speed, then lets it rev up under load. The cycling is to keep the turbo spooled for max output, and an accurate reading.