Help justifying mods
 

When does a mod cost too much before the net gains from that mod are canceled?

I'm referring to smooth hub caps, rear-wheel covers, under belly pan, and front grill block.

Alone each mod may not net a tremendous amount, but in conjunction ya'll at ecomodder have proven that they help.

My question is how to do a quality job w/o breaking the bank. What have you spent on mods and what gains did they net you? (in a nut shell, I know there are pages of A-B-A test results)

Keep reading and do some math. Most mods can be done cheap or free if you know where to look for materials. It also depends on how much gas you burn.

In the garage there is a line that calculates $saved. I'm at $1100 over three years but I don't drive much. I have not spent anywhere near that much on mods. Someone who drives far every day can save quite a bit.

I, personally don't worry too much about the accounting because to me it's an interesting challenge to be the most efficient I can.

The mods you're referring to dleefoto can be done for less than $100 total. Call up your local sign shops and ask how much for a 4'x8' sheet of coroplast (corrogated plastic). . My local sign shop will sell me a sheet for $20. That will be enough to do your rear wheel skirts, front grill block, and most if not all of your underbelly. You'll need to get some hardware from the local Home Depot, and spend maybe $20-30. It all depends on how clean of an install you want to do and how much you care about the body of your car. I see you have a 2010 Ford Focus, so I'm assuming you're going to want to do as little damage as possible. With my Geo Metro, I have plastic bumpers so I don't care about them much and don't feel bad screwing into them.

As for cost:benefit, that all depends on how much you drive. I drive about 30k miles per year, so for me my mods pay off fairly quickly (well, except for the smooth hubcaps). If I save $0.005 per mile for a mod that cost me $30, it will take 6000 miles for that mod to pay for itself (that's going from 45 MPG to 48 MPG). Your cost and mod effectiveness will vary depending on how you drive and how you do your mods. Read up on the 65+ Efficiency Mods and the 100+ Hypermilling Tips links that are at the very top of this page. Those will be a good start. Remember, the cheapest mod is to simply change your driving habits to be more efficient. In my 94 Geo Metro that I had I could average 33 MPG, but with a change in driving style I once got 49 MPG out of it.

Thanks Orangeboy and honestabe for the perspectives! Seeking material was my main concern and knowing that sign shops might be able to supply corrugated plastic is a great tip! I haven't filled out my online gas logs yet but my own gas records checked w/ SG show that I'm 27% over stock combine mpg. I'm looking forward to seeing what some aero mods might yield. Thanks again for your insight.

Right, do the fuel log and see how much you save. I'm saving 40-70% of what I would pay if I got the EPA rating.