Quote:
Originally Posted by hootis
I have a mazda 3 2015 model.
I have a 5-10 minute drive to work, I stop 7 times in 1.5 miles. I'll say every 300meters. I drive home once a month 500 miles round trip. I currently get around 50-53 mpg on highway with a partial front air dam, and I removed the mud flaps.
I was thinking about larger wheels because, I eventually plan to add solar panels and remove the alternator. I figure at a given RPM there would be significantly less resistance than stock, so it would benefit by lowering the rpm and thus internal resistance primarily on the highway in 6th gear, since a transmission swap on a new car is pretty dumb.
I'll look into buying used alloy wheels and building coroplast covers. I also wanted to cover the rear wheel wells, but I don't really have the skills for that, I wouldn't know where to start.
A picture of the coroplast wheel covers would be great, I'll search the fourm first though.
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I'll start with the bolded section.
(No disrespect meant, just a good opportunity to use a meme
)
In all seriousness, engineering rear skirts is fairly simple. I'll dredge up my post when I made them for my ZX2.
Quote:
Originally Posted by BabyDiesel
Finally made wheel skirts that are permanent yesterday! No more hearing them rub the tire if a vehicle gets too close 
This is a simple process that can add a lot of life to your skirts. I went the more expensive route, but it is worth it to me.
Removed old wheel skirts that were held on with duct tape
These are the items used to fasten the new coroplast down. These tabs and 1/4" aluminum bar can be found at Lowe's. I spent ~$12 on this.
Next came measuring the width of the wheels wells. Roughly 30" for the ZX2. The ends are hand bent to fit, making sure they clear the tire at all times. Next, I used 1" screws with a 5/16" head to screw them in place, along with the tabs.
Next is cutting the coroplast to fit WELL. This took longer than I expected, and the time is worth it. Paint them with whatever color you want. I chose black. Screw them down and you have some bangin' lookin' covers now!
Beautiful and functional  |
http://ecomodder.com/forum/showthrea...tml#post476484
The hardest part of this is mounting the tabs and bar flush. The aluminum bar will have to be bent to accommodate your wheel well and tire, as most vehicles do not have the tire inset enough to make it flat. A slight bend will not hurt your Cd though.
A pic of a car similar to yours for reference:
It looks like rear fender is setup like my ZX2 with the backside of the wheel well dipping behind the tire.
You should be able to bend the bar as to not contact the tire while still being close to flush with the body.
Your route, is there another option? Those stops will be dragging down your FE pretty badly. If they are lights, try to time them the best you can. If they are stop signs, I suggest a new route with as few of stop as possible while keeping the distance comparable.
If I were you I would not look for bigger wheels. You already have a decently big tire on your car if it is the stock 205/60R16 @ 25.7". In fact, your car is better geared for the highway than my automatic ZX2! I plugged in the numbers on a gear calculator and you have ~9.4% higher gearing than my car, and this is very unheard of from most manual transmissions. For everyone's info, the 2015 Mazda 3 has a 0.68 6th gear with 3.85 final drive, from
here.
For instance, @ 45 mph, you will be turning 1540 rpm in 6th while I am at 1700 rpm in 4th W/ TCC. Impressive!
I would try to find lighter 16's to save your current tires and keep from buying new tires, and when they wear out, go with a slightly thinner, slightly taller tire if you desire, such as a 195/65R16 or 195/70R16. Make sure they are LRR though, less energy = better mpgs!
Lastly, My thread linked above has pictures of coroplast wheel covers. They were quickly made in less than 2 hours, then painted and zip tied on. 15,000 miles later, they are still doing the job well. Aesthetic leave something to be desired, so I am going with custom painted pizza pans soon
Link for the coroplast wheel covers -
http://ecomodder.com/forum/search.php?searchid=2413364