Originally Posted by +fireamx
Travelling to and from the Dragons run this weekend, I conducted a 440 mile gas mileage experiment.
From Akron Ohio, to just North of Cincinnati, I cruised on Interstate 71 with my Wing in the raised position going South. On my return trip I kept my wing down over the same section of highway.
Variables?
There were little to no crosswinds.
No head or tailwinds.
Going South air temp averaged in the low 50's.
Going North air temp averaged in the upper 60's.
Air Temp at all 4 fill-ups were within 5 to 10 degrees of each other.
Tank was always filled to the very brim to insure accuracy.
Speeds averaged around 72 mph going South.
Speeds averaged about 75 mph heading North.
About a 240' increase in elevation heading North.
I never coasted, and Cruise control was used constantly.
The end result.......(drum roll please)
30.784 mpg with the wing in the "down" position.
28.440 mpg with the wing deployed.
I realize this wasn't a "controlled" test, and I've read where several forum members have posted that they attained higher mpg results the faster they drove. I just thought a difference of 2.34 mpg, was significant enough to mention.
I prefer to believe the increase in MPG is due to the wing being down, and the car is moving thru the air with a little less turbulance.
Oh, and on another leg of the trip home, I was running (with traffic) at speeds of 95 mph (where my audible warning beeper went off) and the car still felt very stable and planted. But I think they programed it to sound off at that speed because any faster, and it would "need" to be deployed to actually do some good.
Remember, this was just a test, do not try this at home. Keep out of reach of children.
It's interesting, and you tried to take into account a number of variables. And you do disclaim saying the test wasn't controlled. Thanks for sharing this here.
But in order for the results to be meaningful, it would need to be controlled.
Originally Posted by MAKIII
some high browed died in the wool all issues detailed out the A** experiment.
Scientifically speaking (high-brow, dyed-in-the-wool experiment mentality), the mileage results you got are "in the noise". As you stated, you've got a number of factors that are not tightly controlled that affect mileage:
- route
- brand and type of fuel on each fill-up
- tire pressure
- weight of the car and contents
- time of day
- position in traffic (drafting vs. leading)
I'd love to get a couple extra miles out of a tank (sounds like you got maybe ~30) but the results are inconclusive to me. One could take any one of the variables (either reported or not reported) and claim that as the reason:
- speed
- temp
- altitude (and atmospheric pressure)
- wind
- unrecorded variables (see above)
Yes, you said it wasn't controlled.
Not trying to beat you up. Just observing that this is like the import tuners putting a chrome muffler (can I say "Fart Can on here?") on a car and claiming 2-3 HP increase based on casual, uncontrolled "before" and "after" observations.
Remember, the
spoiler (it's not a wing) doesn't create additional frontal area when deployed (which would affect aerodynamics numbers); it "spoils" the air flow, disrupting it as it passes over the car. It is supposed to prevent the car from developing excess lift at very high speeds. The general consensus is that it only creates 40 pounds of downforce at speed, above 80MPH. This is enough to achieve the intended effect but is quite modest. Think of it this way: Two or three bowling ***** in the back would be about the same, though more noisy if left loose...Of course if they were "Crossfire" or "AMX" (close to "AMF") bowling ***** we'd have to revisit this...
Again, I am not trying to be mean. I'm an engineer. That's something of a social challenge when stuff like this comes up... I'm just pointing out that nobody should make any conclusions based on the test. I agree, that people should do what makes them happy.
And clearly all that matters is:
Originally Posted by +fireamx
I prefer to believe the increase in MPG is due to the wing being down, and the car is moving thru the air with a little less turbulance.
Reason for Edit: My own compulsive nature - should have said 40lbs of downforce above 80MPH