HAI Experiment

[GasSavers_NovaResource]

Originally Posted by R.I.D.E.

LOL, lets see if your mileage improves in the summer months, but I would venture a guess that you need AC, unless the AC robs you of all that power that is so essential. Of course if you have been logging mileage for any significant amount of time then you would already know if your summer mileage was better.

Yes, mileage goes up in the summer time. But not because the engine is getting warm air it's because the engine gets up to operating temps quicker and because the engine runs hotter. The engine runs more efficiently when the coolant and oil are warm. Warm engine = better fuel economy. Since the engine gets warmer faster and the overall engine temps are higher you get better fuel economy. It has nothing to do with warm intake air. It also has a little to do with summer blend fuel vs winter blend fuel.

WAI does not improve fuel economy. It just robs power.

As for A/C, yes, it robs some power but it will also shut off under harder acceleration to bring back that power. Then, when the throttle position is smaller under cruise conditions, the compressor kicks back on. Do I NEED the A/C? Nope. Many times I won't use it at all. I park in the shade during work, use a sun shield in the windshield and have tinted windows. All that helps keep the interior cooler so I don't NEED the A/C.

Originally Posted by R.I.D.E.

With the 4 simultaneous methods of measuring fuel consumption on the Insight, it's easy to determine the effectiveness on any modification. In the last few days the temps here were approaching 75 degrees, so I took the grille block out and noticed an immediate drop in mileage.

And you think that was because it was getting cooler air? Did you ever consider the decrease in MPG was due to making the car less aerodynamic? The air flowing into the grille area was creating drag.

[R.I.D.E.]

You have no idea of what you are talking about.

I have the means to test every assumption, and prove or refute them.

My car takes 1 mile to warm up at 70 degrees, 1.5 miles at 32 degrees.

Warm ups drop my average on a 40 mile round trip by less than 3% in winter, 2% at 70 degrees.

I have the ability to measure the precise fuel economy during the warm up cycle alone.

You do not.

I can measure my mileage in .3 mile increments.

You can't.

I can drive your car and get 30 MPG.

You can't.

My wife got 22 MPG in her Murano, averaged for 30 k miles. That's a 245 HP V6 which eats Hundais for hors d'ouvres.

I got 30 MPG in her Murano driving down the interstate.

My car uses more fuel in one rapid 0-60 acceleration than it does in a warm up, covering 1 mile.

My mileage loss is much greater from having to stop rapidly for 3 traffic lights than any warm up, regardless of the ambient temperature.

Maybe you should try reading the wealth of information, and actually try to learn something from the members here who regularly beat EPA figures by a whole lot more than 5%.

Your test was flawed before it began because you had deluded yourself into thinking it wouldn't work. Changing your driving style would increase your mileage by 25% over EPA, but then you wouldn't need all that power that you so sorely missed when your WAI was "working".

Don't read, learn nothing, waste energy.

Who looses?

You.

I travel 3 times as far as one of your vehicles and 4 times as far as the other on a gallon of fuel. My wifes Rogue has averaged 26 MPG since mile 1, and should hit 30 MPG this summer, maybe even better.

I can probably make it from coast to coast on the gas you use to fill up your 2 vehicles.

regards
badger

[theholycow]

I still don't get why so many people seem hung up on it having to apply universally, rather than (like most other modifications and even driving techniques) working for some cars/people while failing for others.

[GasSavers_NovaResource]

Originally Posted by R.I.D.E.

I have the ability to measure the precise fuel economy during the warm up cycle alone.

You are my hero.

I already have beaten the EPA by 25% or more many times just by my driving style. But I also live in an area with lots of hills and city driving that hurts mileage.

Bottom line: a warm air intake does not improve fuel economy. It hurts engine performance and lowers efficiency. Lower efficiency lowers fuel economy. A warm engine (coolant and oil) helps fuel economy, warm intake air does not. I've proven it myself (which you asked me to do). But don't believe my test, others have also proven it doesn't work: http://www.metrompg.com/posts/wai-test.htm

[theholycow]

Originally Posted by NovaResource

Bottom line: a warm air intake does not improve fuel economy. It hurts engine performance and lowers efficency. Lower eficency lowers fuel economy. A warm engine (coolant and oil) helps fuel economy, warm intake air does not. I've proven it myself (which you asked me to do). But don't believe my test, others have proven it doesn't work also: http://www.metrompg.com/posts/wai-test.htm

Bottom line: There's nowhere near enough data to apply it universally, especially in the face of equal amounts of data supporting the other side of the argument. It has those effects on your car with you driving in your climate on your roads and your schedule. It also didn't work for the test on mterompg.com which we've already discussed quite thoroughly.

[R.I.D.E.]

Same route today.
From cold start.
.2 mile 13.4 MPG.
.4 mile 25.4 MPG
1.0 mile 34 MPG
1.5 mile 45 MPG (warmed up to normal 6 bars)
4.0 miles 54 MPG
8.0 miles 60 MPG
20.0 miles 62.2 MPG
Conditions heavy rain standing water on the road, typically my MPG for the same route is 70+.
One hour later another cold start, mileage dropped to 60.6 at 6 bars temperature. Reset trip A mileage.
Note the mileage dropped from 62.6 to 60.6 on the second warm up on the same trip distance.
Return trip with no warm up 61.8 MPG, less rain and standing water but a headwind of about 15 MPH, total effects just about the same.

Now notcie the loss of mileage due to rain and standing water on the road as well as wind on the return trip.

The cumulative effects of those conditions was a 10 MPG loss in mileage, or about 16 %.

The cumulative effect of two cold starts on the outbound trip.

1.2 MPG.

The shorter your trip the greater the losses due to cold start as is easily shown by my initial mileages.

So Nova, there is empirical evidence that demonstrates the cost of cold starts and their overall effect on trip mileage.

Your assumptions about cold starts being the major (your statement) cost of poor mileage just doesn't hold water. The effect of cold starts is definitiely amplified by short trips and the percentage of distance travelled without the engine at operating temperature.

If that was my situation (it is not) I would get a block heater.

My response to your prior post was exactly the attitude you displayed and exactly the response you deserved. If your perception is that it is insulting, then the problem is between your ears.

regards
gary

[GasSavers_NovaResource]

The good news is that now the factory inlet is hooked back up and the engine is getting cold air again the power is back and mileage is slightly up. Round trip to church Sunday (26 miles) yielded a average of 27 mpg for just that trip. After a round trip to work yesterday (35 miles) it's averaging 24.5 (traffic sucks).

[dkjones96]

This is one of those weird ones. Nobody really gains any monetary by this being true but some people still stand by it.

I agree with THC that it can't be a universal yes or no. My 360 has iron heads and letting the engine suck in 150+ degree temps is more prone to pre-ignition in that engine than a newer aluminum head v8 would be. Not saying that is the cause of my results, but it's likely an issue.

For all we know the type of fuel injection system can cause a yay or nay. Speed-density vs mass-flow, TBI vs direct-port, fuel injection vs carburetor, electronic spark advance vs mechanical spark advance, 160 degree thermostat vs 195 degree thermostat.

Too many variables. Take a mass-flow system for example, The mass air flow meter works by resistance. As the fine wire heats up resistance increases so the sensor converts that to mass and sends it off to the ECU. As ambient temps rise, the temperature of that sensor at a given air flow rise and cause the sensor to report less air than may actually be going through the sensor. For all we know this means that the engine hangs on the lean side of stoich more often than not and that causes the increase in mileage.

In a speed-density system it might already have a calculation for how much extra heat is expected to enter the air before the port at a given IAT. Introducing that heat before the sensor means it is still compensating for that even though the heat won't enter the air stream and this cause the engine to hang on the rich side of stoich. That would account for my losses but this is all speculation. I don't know where the compensation for that ends or anything. It's only provable on a dyno that, unfortunately, we don't have here at work anymore.

[R.I.D.E.]

Same trip today weather conditions were 50 degrees clear and low humidity.

38.5 miles, 74.7 MPG.

Compare that to yesterdays trip with significantly lower mileage due to heavy rain.

Inbound the first half of the trip was 78.9 MPG, starting from a warm engine.

After an hour of sitting the return trip mileage dropped to 75.4 MPG, then the rest of the trip resulted in the recorded mileage of 74.7 for the total distance travelled. The return trip was into the wind and an elevation change of + 70 feet. The first half was with the wind and a -70 foot elevation change.

The largest factor in the difference in mileage in the two trips was due to weather conditions and standing water on the road due to rain yesterday.

As previously stated the mileage difference due to weather was 10 MPG. Actually is was closer to 13 MPG.

All other factors being identical, the comparison between MPG losses due to cold starts and weather provide a good comparison.

13 MPG difference due to lousy weather.

Difference due to cold starts as stated previously.

regards
gary

[GasSavers_NovaResource]

Originally Posted by dkjones96

For all we know the type of fuel injection system can cause a yay or nay. Speed-density vs mass-flow, TBI vs direct-port, fuel injection vs carburetor, electronic spark advance vs mechanical spark advance, 160 degree thermostat vs 195 degree thermostat.

Too many variables. Take a mass-flow system for example, The mass air flow meter works by resistance. As the fine wire heats up resistance increases so the sensor converts that to mass and sends it off to the ECU. As ambient temps rise, the temperature of that sensor at a given air flow rise and cause the sensor to report less air than may actually be going through the sensor. For all we know this means that the engine hangs on the lean side of stoich more often than not and that causes the increase in mileage.

In a speed-density system it might already have a calculation for how much extra heat is expected to enter the air before the port at a given IAT. Introducing that heat before the sensor means it is still compensating for that even though the heat won't enter the air stream and this cause the engine to hang on the rich side of stoich. That would account for my losses but this is all speculation. I don't know where the compensation for that ends or anything. It's only provable on a dyno that, unfortunately, we don't have here at work anymore.

Great post and something I've said all along. Older cars with MAP tend to show gains in mileage do to the computer being "fooled" by the higher temps. However, more modern MAF equipped engines compensate for the higher IAT and keep the mileage the same. In the long run for modern engines it's better to keep the IAT cooler to prevent detonation, to keep the ignition from being retarded and to keep the power.