weight VS. wind
 

Okay, here goes, first real thread and question.

I've been thinking of a few mods with my EXTREMELY limited mechanical ability. My first thought is to change my fancy ford escort wheel for the stock steel clunker with moon caps. I was wondering if ...
1. there is a big boost from this.
2. if this aero mod will be offset with the increased weight of the steel wheels. There will probably be a 25 percent increase in weight.... will I save fuel??

I looked at mods like basjoos?(sp) and wonder if that stuff he surrounded his car with weighs so much that he had no net benefit's.

What I need to find out really is.... will added weight offset an aero mod. and how do you calculate such a thing. sorry for the amateurish question, but I am new. :rolleyes:

weight vs. wind
 

http://ecomodder.com/forum/showthrea...nnel-1924.html is an excellent thread on this. Bearleener found a handy rule where reducing your coefficient of drag by .01 is equivalent to shedding 220 pounds. However, I believe that figure is only accurate at a constant 60 mph. Since weight has a greater relative impact at lower speeds, and especially under acceleration, the practical equivalent should be considerably less than 220 pounds.

Here Measure the drag coefficient of your car - Instructables - DIY, How To, ride is an excellent instructable that should be able to tell you how much of an improvement those wheels make. Of course, the simplest solution is always to hook up the ol' scangauge or neighborhood friendly gas station and take em out for some test runs...

wanna bECO, wanna post a (modest) picture of your rims? Might help if someone wants to comment on your particular set-up.

Vanner is right. At a steady speed, momentum (weight) works for you almost as much as the higher rolling resistance works against you.

My goal is to find very smooth wheel covers for my two front wheels and rear wheel well skirts to cover the back.

okay, here is a pic of the Rims.... I know, I know... they're pretty dope :D... but then again, so is the whole ride. So, will i gain any mileage changing to steel rims with moon caps, I don't really care about how she looks.... she is just transpo after all. :thumbup:

I find that those new to FE tend to give mass much more weight in their modding pursuits than it deserves. TEHEHE

Anyway, I would focus on aero and say screw it to weight (at least as far as the weight of aero mods are concerned). It's not a 1/4 mile strip so it's not as important as it is to all the tuners.

If you want to just try before you buy, Cover the outside of the wheel with cardboard and duct tape. If you are able to take the wheel off, you could cover up the inside parts of the spokes as well. Make sure you do not get any cardboard/tape pinched between the wheel and the hub when you put the wheel back on.

I would say the answer depends on what type of driving you do. If everything you do is city, then I would dump as much weight as you can. If everything is highway the aerodynamics are more important. For a compromise, why not just get some old election signs and zip-tie them to your bling escort rims. You get better aero, the reduced weight, and you don't need to buy new wheels. In the event you need to take the wheel off, just cut the zip tie.

To say nothing of the extra style points, and the chance to end up on someone's ricer site.

i know my areo mods on my CRX have added a few hundread pounds.. just by know what materials when into them , but my MPG has gone up. so I have decreased my drag more that the weight that was added added..

Doubt I'll end up on a ricer site:
http://www.ebacherville.com/AreoCRX/skirts%20far.JPG

WOW! that is one sweet ride... I guess election signs will disappear in my hood this year!

Well, you could turn them inside out so you don't drive around with advertisements.

I used homebuilt aircraft aluminum construction technology in constructing my mods. The boattail weighs about 50 lbs. (but I removed at least that much weight in removing the stock steel and glass hatch),the nosepiece weighs about 20 lbs., the wheel well covers about 4lbs (front) and 2lbs. (rear) each, and then a few pounds for the coroplast underbody.

wanna BECO,I did an installment on wheels and tires that will give you some numbers to compare.I've not touched on weight as I'm still doing aero.The weight difference between the "clean" Moonies and heavier steel wheels,shouldn't impact mpg with respect to the "dirty" alloy wheels.Consider brake cooling if your a urban street screamer.If you are easy on the binders,Moonies are a great way to go.

Don't swap wheels, add a set of "screw on bonneville salt flat discs" in your existing wheel size. (don't buy the snap-on ones they also sell, they won't work on your aluminum wheels)

Drill and tap the aluminum wheel lip using the factory holes in your new caps as a guide. Fasten them using #8-32 or #10-32 phillips pan head or button head allen machine screws will do it. The covers come with three evenly spaced holes already drilled in them.

There is another thread somewhere on this exact thing.

I don't think this is true. Could you explain either what you mean or why you believe it to be true (or both)?

220-pounds
 

It would be valuable for them to cite the test vehicle weight used in the "rule of thumb",as a 220-lb reduction in a Cadillac DeVille would probably show a different reaction,say to a VW 1-liter car.Perhaps a percent mass change per mpg percent change would be more helpful.