I just re-installed my intake (3.5 diameter pipe) about a month ago. On my latest fill up i'm already at 330 miles on one tank. Before I used to have to fill up at 270 and that was a stretch. Anyone else using an aftermarket intake and notice that big of a gain?
Can an Intake give better gas mileage?
- Thread starter ryans
- Start date
You cannot determine MPG with any certainty with a "full tank" method.
The OEM fuel gauge is extremely inaccurate at the ends of the scale. The reason why here: http://auto.howstuffworks.com/fuel-gauge1.htm
Here is how you measure MPG so you can talk about it:
1. fill tank and reset trip meter
2. drive around
3. fill tank, record the fuel dispensed and miles on trip meter.
4. Keep a log of date, amount of fuel and miles
5. Repeat process 3-4 times, take average and report back.
You should strongly doubt anything simple that raises MPG for two reasons: HP and fuel efficiency have a direct relationship and auto makers are under extreme pressure to raise MPG. So if it is simple and cheap it would have already been done....feel free to try, but be extremely skeptical of positive measurable results.
Edit: MashimaroNSX brings up a good point. I meant "simple" in the quest for more engine power and/or efficiency.
Drew
The OEM fuel gauge is extremely inaccurate at the ends of the scale. The reason why here: http://auto.howstuffworks.com/fuel-gauge1.htm
Here is how you measure MPG so you can talk about it:
1. fill tank and reset trip meter
2. drive around
3. fill tank, record the fuel dispensed and miles on trip meter.
4. Keep a log of date, amount of fuel and miles
5. Repeat process 3-4 times, take average and report back.
You should strongly doubt anything simple that raises MPG for two reasons: HP and fuel efficiency have a direct relationship and auto makers are under extreme pressure to raise MPG. So if it is simple and cheap it would have already been done....feel free to try, but be extremely skeptical of positive measurable results.
Edit: MashimaroNSX brings up a good point. I meant "simple" in the quest for more engine power and/or efficiency.
Drew
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Well actually something as "simple" as making the cars overall weight lighter has been shown to improve gas mileage. However in terms of an intake I highly doubt it will give you a substantial amount of fuel economy if any.
I think your driving habits can have more of an impact to your mileage than an intake can. Perhaps you kept your foot out of the throttle more on the last tank.:smile:
more air = more fuel :smile:
so everything staying the same. if you put in more air, you'll need to use more fuel.
so you should be getting worse mpg, unless you have a restirction in your intake and it was causing rich running conditions.
so everything staying the same. if you put in more air, you'll need to use more fuel.
so you should be getting worse mpg, unless you have a restirction in your intake and it was causing rich running conditions.
Drew has it accurately.
When you drive around town, your engine is putting out very small amounts of power compared to the maximum it could. Around town is low throttle openings and low load conditions.
Because of this, there is little air flow into the engine. Changing either intake or exahust efficiencies, even if they had an improvement, would be very small based on the small amount of air needed at these engine loads.
The intake system wants a vacuum in the intake manifold so that there is good mixing and fill of the cylinders. Changing the inlet on the other side of the air filter (up stream) will have a very small difference in how the air finally enters the cylinders, especially at low load conditions. In other words, it won't help or hurt the low load efficiency of the engine.
As most posters have said, do not expect to be able to improve your fuel mileage much, if at all. That is, unless you have a problem you are fixing, or you can seriously lower the weight of the vehicle, or you drive with a lighter touch on the throttle (even lower loading).
YMMV (but only a little
When you drive around town, your engine is putting out very small amounts of power compared to the maximum it could. Around town is low throttle openings and low load conditions.
Because of this, there is little air flow into the engine. Changing either intake or exahust efficiencies, even if they had an improvement, would be very small based on the small amount of air needed at these engine loads.
The intake system wants a vacuum in the intake manifold so that there is good mixing and fill of the cylinders. Changing the inlet on the other side of the air filter (up stream) will have a very small difference in how the air finally enters the cylinders, especially at low load conditions. In other words, it won't help or hurt the low load efficiency of the engine.
As most posters have said, do not expect to be able to improve your fuel mileage much, if at all. That is, unless you have a problem you are fixing, or you can seriously lower the weight of the vehicle, or you drive with a lighter touch on the throttle (even lower loading).
YMMV (but only a little
Just filled up.
Used 14.632 Gallons
Mileage 330 Miles
Gas Mileage = 22.55 mpg.
Would that calculation be right? Or would I have to run it totally dry to calculate the gas mileage?
The gas light never even came on.
Used 14.632 Gallons
Mileage 330 Miles
Gas Mileage = 22.55 mpg.
Would that calculation be right? Or would I have to run it totally dry to calculate the gas mileage?
The gas light never even came on.
Hot engine air? 
doesn't the NSX gets its air from the scoop outside of the car and transfers that to the filter element ? so in theory isn't the stock intake more of a cold air one?
doesn't the NSX gets its air from the scoop outside of the car and transfers that to the filter element ? so in theory isn't the stock intake more of a cold air one?
Yes, that's the correct method and also consistent with my mileage as well. I average almost exactly 22.5 mpg during normal driving. I run the stock airbox and filter w/ Cantrell scoop, BTW.
If you run it totally dry you won't make it to the gas station to see how much you've used. :tongue:
Correct; you don't need to run it dry.
Calculations will be more accurate if they are totalled over the course of several consecutive tankfuls, with similar driving conditions.
A clean air filter can give better gas mileage than a dirty air filter. So if you're looking to see the difference, make sure you're using clean air filters in both cases.
At one point I was using a K&N cone air filter, and I since restored it to the stock airbox. There was zero difference in gas mileage (with clean air filters in both cases), and no noticeable difference in performance. There was a difference in sound, though.
Calculations will be more accurate if they are totalled over the course of several consecutive tankfuls, with similar driving conditions.
A clean air filter can give better gas mileage than a dirty air filter. So if you're looking to see the difference, make sure you're using clean air filters in both cases.
At one point I was using a K&N cone air filter, and I since restored it to the stock airbox. There was zero difference in gas mileage (with clean air filters in both cases), and no noticeable difference in performance. There was a difference in sound, though.
You did not state why hot air is more efficient. My belief is that hot air is not more efficient. At given pressure difference (say across the throttle body), a hotter air flow will contain less O2 molecules than a cooler one (hotter -> less density). As WOT, you want as much O2 in the engine as you can get... so hotter is less power, at WOT, all else being equal.
As far as normal cruise mode (partial throttle), hotter air will still flow less O2 molecules than cooler air. However, the ECU meters the fuel to match the air very accurately so you don't waste fuel when the temps go up. What happens is that, for a given throttle position, the car will just accelerate less quickly. The driver usually just cracks the throttle open a little more in this case, which restores the desired O2 level, and gives the performance the driver wants. But, the ECU still uses the same fuel for the desired power.
Hot air decreases maximum power. Cooler air is a benefit to maximum power.
+1 That is why drag racers post better times on Friday night qualifying and rarely improve their times during the main event.
