how to help my matrix

[Varn]

excellent You are my kind of guy probably somewhat of a packrat. How many miles do you figure it will take to break even?

I am hopeful that My front mod on my camo van will pay for it self in one year. About 8000 miles.

Originally Posted by Weather Spotter

Here is my cost data for the wheel skirts:
materials:
braces $8.00 bought two used one, cost is for both
screws $0.50 used some I had, but bought some to refill stock, cost is for ones used
sheet steel 0 free, had it laying around
brackets 0 free, taken off junk stuff
hinges 0 free, taken off junk stuff
Primer $5.00 Used 95% of one can
paint $14.00 bought two 8 oz cans used 1.5
clear coat $5.00 used less than half of can
Total $32.50 (only what was used = $22)

Time:
design time 2
build first bracket 2
build first skirt 2
mount and tweak first skirt 1
paint first one 0.75 (not counting dry time)
build second brace 0.5
build second skirt 1
mount and tweak second skirt 0.5
paint second one 0.75 (not counting dry time)
Total 10.5 hours

Testing:
Time:
planning 0.5
first ABA test 3.5
coast down 1.5
second ABA 2.5
Total 8 hours

Costs for testing:
gas 7 gal
cost $19.00
miles 280


So in total I have about $50 invested in skirts and testing. I also have 18.5 hours invested in making and testing them.

Testing takes a lot longer then I had thought But good data is nice to have (and share)

[Weather Spotter]

I am not a pack rat, I just keep things I know I will use.

As for the pay back time, it will depend on how far I drive. With all my mods I am getting at least 2.5 MPG better. That is a change of +5% min.

All my mods cost my ~$45 to make (most of that cost is paint). Testing also adds another ~$28 in gas. All in all it will take a while.

I need to do some more testing to determine exactly what all the mods gain me. I have hard data (short runs but something) that show a .4 to .66 MPG gain off of the wheel skirts. The Kammback coast down numbers show a 2% aero gain (or about .5 MPG). I also did an upper grill block and a side mirror removal. Each of those is helping but I doubt that they both add 1.5 MPG. So I know that my testing numbers are a bit low.

I might find time this week to do some more testing. If I can only do one set I think I need to do a stock and full mods. I want to do each by them selves, but it is hard to justify 2 hours on each mod + all of them http://forum.ecomodder.com/images/smilies/mad.gif It also costs me 1 to 2 gallons of gas for each test (to get a valid data set) or about $5 a test. So is $5 and 2 hours a test worth it?

[Weather Spotter]

I had fun today before I left for home (320 miles) I changed my sign on the back of my car from 42 to 43 MPG. It is my 90 day average. Last tank was 46.6 (my best) and my current tank will be over 47.8!!!!!

[Piwoslaw]

Originally Posted by Weather Spotter

I had fun today before I left for home (320 miles) I changed my sign on the back of my car from 42 to 43 MPG. It is my 90 day average. Last tank was 46.6 (my best) and my current tank will be over 47.8!!!!!

Are those digits magnets? They should be, as you'll be changing them a few more times...

[Weather Spotter]

Originally Posted by Piwoslaw

Are those digits magnets? They should be, as you'll be changing them a few more times...

yep, I have a roll of magnet material, I bought mail box stickers (3") and stuck them to the magnet stuff, then cut them out. It cost me $4 and it is fun to advertise how far over EPA I am. It also gives people an idea why I do what I do.

[Weather Spotter]

I also made numbers so that I can go up past 50! I made 0-9 and an extra 4. If I get to 55MPG I will make an extra 5 (one can only aim high).

[Weather Spotter]

Update:
I did some steady speed ABA testing today On the Kammback.... it showed a .91 MPG gain.

A=45.15
B=45.98
A2=44.98

So the coast down showed a 2.34% better aero (at 60MPH) and the ABA test at 55MPH is .91. to me that sounds about right (2% aero = 1MPG).

[MetroMPG]

Originally Posted by Weather Spotter

Update: after 700+ miles on the car I have had no issues! No rubbing or loose parts!

With all my mods I have seen a 2-3 MPG gain (very conservative number).

Congrats! I love the magnet signs on the back of the car too. Explains everything at a glance.

Did you hear back from Ben about the decals? "EcoModder" on the back will complete the picture

As for testing - is the time and expense worth it? I think so. It separates us from the scammers who make ridiculous, unsubstantiated claims.

[Weather Spotter]

I have not heard back yet on the stickers, yes they will add a nice touch!

More test data to come after dinner. I did ABACADAEAF testing, which cut out about 30% of the time.

[Weather Spotter]

Testing update:

Kammback data:


Graph:


I also ran a "B" test (was letter F) will all my mods on. I used the data from my last test with my side skirts off as the "A" data.

Graph: