Install front spoiler.... better MPGs?

sixt9coug

Member
Sep 30, 2009
222
3
19
Norwalk SoCal
Ok, before you think I'm some kind of nut.... well, I keep pretty accurate fuel economy records.I use Fuelly primarily, but even prior I used to check my MPGs EVERY SINGLE TANK to track it.

Here is the Mustang Fuelly page for example....

https://www.fuelly.com/driver/sixt9coug/mustang?fu=2501302

So you see, I've got a few tanks of fuel as an example. Getting most of my tanks in the 19-21 mpg range was pretty common until a couple of weeks ago. I installed a Mach1 style front spoiler on the car.

2012-04-15171913.jpg


No other changes were made at that time.

Now... I ran out the last of the 3/8 of that tank that was in there and it was normal. On the low side of normal, but not out of line for my averages.

However, on the first two full tanks of gas that I have run through, my mileage jumped to 21.9 and 22.0 mpg average. Easily.

I got 340, and 333 miles out of each of those tanks. I feel I probably had another 20 miles or so in the tank today even.

My driving style has not changed, my commute certainly has not changed, and as I said before, there were no other changes made to the car. I cannot positively contribute the change to the spoiler, but so far it's pretty compelling. However, I will keep track of it.

Anyone else running one and notice the same thing?
 
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The less air going under the car the better. If you lower it some you might see another mpg gain. I'm guessing you do a lot of highway driving?

I just installed the Boss front valence and splitter on my car. It's not really a good test since my driving route is all over the place, but I did just get 23.6 mpg where my previous best was 23.3. I think the 23.3 was mostly driving easy and I got on it some with the 23.6 tank.
 
I guess anything is possible. But, where does the deflected air flow? Is the air directed up into the rad or is it just spilling the air to either side? What's happening here will make a difference.
 
Husky. What's the difference in fuel economy between the cooler months and summer months. I was about to say winter and summer, but I remembered you don't drive your car in the winter at all.

Kurt
 
Don't forget also that "winter" fuel and "summer" fuel are different mixtures, and your fuel mileage WILL be better on "summer" gas. ;)

That said, improved aerodynamics will help with mpg. :)
 
I think you're some kind of nut. :D

Any other variables to consider? Different weather? Same basic driving routine/routes/time of day?

Weather has been pretty consistent out here lately. We are hitting a "gloom" time of the year. Higher than normal humidity (around 45-55% RH for us) and the mid 70s for temps. Overcast skies for the better part of the day too.

My commute is the same through the week. I really only drive the Mustang during the week too. 32 miles each way to work every weekday. 64 miles a day, around 325 miles a week. Fill up Friday after I make it back home, start running it back down Monday. Leaving work on Friday with the needle not even touching the red zone on the fuel gauge was throwing me off. Normally it's juuuust touching it, and it's enough fuel to get me home with ease. However, the last two weeks I've had slightly more.

Also, I thought summer gas was where your mileage took a dump? I thought that's when they dropped in more ethanol to reduce emissions.
 
Summer vs. winter fuel blends will differ depending on where in the country you are.

As far as my mileage is concerned, I have no idea. When I installed the 3.73s I never fixed the speedo gear, so I can't figure mileage without doing some algebraic gymnastics that I don't really feel like doing.

My mileage ain't that great, but it still beats the snot out of what my V10 Excursion gets, so I still call my 95 my "green" car. :D