Complete newbie here trying to squeeze 45mpg out of a '98 Corolla
 

I'm a soon-to-be sophomore in college and I've just stumbled upon ecomodder. I've been reading the forum and blog postings for about five hours now and I am completely obsessed. I have already ordered my ScanGaugeII and I'm going to see what I can do.

Current estimate is about 30 mpg (based on about 300 miles to a 10gal tank). I have tentatively set my goal for 45 mpg. I don't know if this is reasonable because I have not been practicing any of the 100+ driving tips before tonight and I don't know how much improvement those will yield before any modifications. I can really feel (and hear) the drag on the car when I approach 70 mph though.

I mentioned my new obsession to my mother in passing and she is adamantly opposed to my altering anything that will in any way hinder my safety (namely, removing mirrors), so I've decided to stick to the bottom of my car. Also, (and saying this as a newb), the '98 Corolla's profile looks like it will gain little from anything up top short of a complete boat tail.

Here's what I want to do:
Grill blocking
Belly cover
Rear wheel skirts
Front and rear wheel deflectors
Front and rear wheel boat tailing

All of my mods have to be easily removable so my mother will approve. I plan on using coroplas for the belly cover and perhaps the rear wheel skirts if I reinforce it with some sort of metal skeleton. As a slightly less removable option, I really like the painted screen method used here. http://ecomodder.com/forum/showthrea...tors-1209.html This is certainly an easy method, but will it perform as well as coroplas?

The deflectors and boat tailing I want to do with some kind of plastic perhaps reinforced with a metal frame. I see a lot of people mentioning using lexan or other plastics that can be shaped easily with heat. Does anyone have any good sources of info on how to obtain/work with these materials?

Here are some paint mockups of what I'm planning. (note the night time atmosphere. It's 2AM and I'm so excited I can't sleep).
http://www.antiyawn.com/uploads/ecomodcar1.jpg
I plan on having the deflectors and boat tails on the back connected by the skirt. This will cover the wheel on three sides. I could maybe connect the underbelly to the enclosure on the inside if the suspension doesn't interfere.

http://www.antiyawn.com/uploads/ecomodcar2.jpg
I'm fairly certain that the openings on the bottom do nothing for the engine, so I opted to cover all of them.

Being a college student, I can't see myself spending more than $200 on this project (especially because I just bought a $150 ScanGauge). I do have plenty of time though.

If you could offer any suggestions about what kind of materials to use or modifications to make, I am all ears. I will conduct a test on the unmodified car as soon as I get my computer.

Ok, well first off, welcome to the site.

Before, you go to crazy on aeromods (though they're not a bad idea, just not the first thing I would do for improvement), get your scangaugeII. Once you have that, you'll be able to determine if you could improve your millage just by changing your driving habits. If you haven't red them already, read the 100 + tips to getting great gas millage, there is some really good stuff in there. After you read that and see what your MPG is using those techniques, then I would recommend the aeromods you're looking at because aeromods will only show small improvements, where adjusting your driving will yield better % results.

But back to your aero stuff. I have a 1996 Camry that EPA est. got 21mpg and I'm now doing about 33mpg in the city and upwards of 45mpg on the highway with and that's without aero mods to it. I just recently built air dams for the front grill, and you're more or less right, those holes on the bottom of your corolla are similar to the ones on my Camry and they don't do a whole heck of a lot. I was able to block off all the holes on the bottom and leave my grill open and my temperatures are still stable, but as always, YMMV. But, when you're looking to make the blocks for those holes, consider using pink insulation foam. It's $10 for an 8'x3' sheet of the stuff and then get some sandpaper, around 600 grit is what I used and it worked great to shape the piece. Cut a template with cardboard and then transfer it to the foam board, use sand paper to get it to fit snuggly into the hole and then to hold it on I used packing tape around the edge because it seemed to stick to the foam better then duct tape did. I also used some cheap $0.99 spray gloss spray paint to make it match the color of my car.

Good luck, looks like you have some work ahead of you.

Welcome to the site! It looks like your ready to go. :) That is great, but as NoCO2 said your largest gains will be from driving style. In fact, if you have a manual transmission I'm absolutely sure you could get 45 mpg without any modifications at all. I have a 2003 Matrix (larger and heavier than your Corolla) and I have gotten 43 mpg under some bad conditions and without hardly any mods (I had a grill block at the time). I'm sure I can get 45 in it, so I'm sure you can get that in your lighter and smaller Corolla (since they went a lot larger in 03).

Welcome to ecomodder! You look like you're off to a good start...where're you going to skool?

I'm going to be a sophomore at MIT this upcoming year :)

MIT, what a terrible skool.

Welcome and VA represent, lol.

Complete newbie
 

As others have said,welcome! I noted your plans and here's my suggestion which dovetails into what others have already said.Consider all your options for driving technique and how that can impact your mpg,then consider a little more home work.I have posted a number of installments on aero-mods with some quantified results from published studies.I haven't done boat-tails yet,however you said you wouldn't be doing that so everything else you mentioned has been covered.If you will study the numbers,you should be able to "build" the Corolla on paper.If you were to rely exclusively on streamlining to push the car from 30,to 45 mpg,you would have to reduce drag by 100-percent,no mean feat! If you'll spend a little additional time going into the project you may spend your time much more efficiently.Happy fabricating!

Yes, planning your aero mods is fun, but basic maintenance (new air filter, engine and tranny oil changes, good brakes with calipers that aren't sticking, etc ...) and driving style changes will save you a lot more.

I had a 1996 Civic with slightly wider tires, aftermarket intake and exhaust and for the most part, i drove it like I stole it. I once had 4 sequential tankfuls that each averaged over 45mpg in the middle of summer. :thumbup:

Your goal is easily attainable ... but aero won't have a lot to do with it.

I'm not much of a gear head (I mean, I can change my oil, replace my starter) so do you have any sites or resources that will tell me how to adjust these kinds of things?

If you don't know where to start with DIYer maintenance, I'd get a Chilton or Hayne's manual for your specific car ... should be $15 or so.

I assume you've upped your tire pressures to the max (or close to it)?? That's a freebie. :)

I suggest getting the toyota factory service manual, either PDF or paper. It might cost $60 in paper, but it will have the correct and specific information on what every little goober in the engine compartment does, and why. Read it from page 1 to page 450 (yes they are big) and you will understand how the car works.
If you can change a starter motor, the chilton/haynes will not give you much more than you already know.

You might as well also start learning one of the MIT mottos:
"Before I came here I could not spell Engineer. Now I are one."

From the toyta site:
Question
Whom can I contact to order an Owner’s Manual, Repair Manual or Wiring Diagram for my vehicle?
Answer
Toyota service publications, including Owner's Manuals, Repair Manuals, and Wiring Diagrams may be purchased from our Material Distribution Center or your local Toyota dealership .
Online access to Toyota reference materials may also be obtained through a subscription to our Technical Information System (TIS).
To contact our Material Distribution Center, please call 800-622-2033 or 310-761-9400 between 7 AM and 5 PM Pacific Time, Monday - Friday.

manual or automatic? 45mpg with a manual corolla is easy as pie. Automatic not as easy. Whats your daily drive like? Lots of city?

So, back to one of the original questions, where do you guys (people that have done very nice professional looking mods). I am looking for materials like Coroplast (sp?), fiberglass materials, bracing (1/8" or 1/4" aluminum). Anybody that has a good location for materials in upsatate NY (near albany) would be appreciated too :D

It's an automatic. My daily drive is typically just city, but occasionally I do go to see my father who lives about 40 miles or so away.

Coroplast is avaliable at sign shops or plastic material houses. Fiberglassing materials are avaliable at home improvment stores, autobody supply shops and even local autoparts stores. Extruded aluminum is avaliable at local hardware stores, home improvment stores, metal supply houses. I sometimes use www.mcmaster.com for some elusive materials.

I just went to AIN Plastics today looking for some coroplast, but the lady at the store recommended expanded PVC or Polycarbonate. PolyCarb is more expensive and more durable, but I have to spend a minimum of $75 anyways (store policy) which will give me enough of both, and I'm not really worried about scratches or dents.

The PVC is very flexible and it doesn't snap when folded to extremes. When heated, it seems to crease instead of curve. I'm not really concerned about this, it's flexible enough to curve when not heated. I'll just have to make sure to force it into place with a strong frame.

Does anyone here have any tips regarding these materials?

Yikes, $75 is pretty steep. I only paid $30 for my 4'x8' sheet of coroplast. No need to get anything more durable, this stuff won't just fall apart or crack. I'd try to find another place that sells it.

Well, yeah, the PVC is $30 for a 4x8 sheet too, but I'm probably going to use it for more than just the underbelly cover (wheel well covers, air dams, boat tails, etc). I'll make use of the other 2 sheets I have to buy.

I don't think coroplast would hold up for most of these jobs, and I might as well use the same material throughout to keep the look consistent.

Trial 1
 

I had some time yesterday, so I went ahead and bought the expanded PVC and began to mod my car. So far I have done an air dam to cover the extraneous grille on the bottom of the front bumper as well as a belly cover that covers about 2/3 of the bottom of the car. I attached it with screws and zip ties and I'm pretty pleased. Especially because the stuff was unaffected by a rather brutal rainstorm last night.

Haven't done any tests, but I have noticed that it's quieter on the highway. Also, the coolant temperature has gone up from 180f avg to about 200f avg. Sometimes it gets up to 207f. I live in a very VERY flat town, so I'm not too concerned about the engine temp (should I be?). Also, this is when it is 85-90f degrees outside, so I don't expect the car to be hit with much worse. If this is a major problem, I will just move the license plate over and cut a hole for intake (my radiator is in the center).

http://www.antiyawn.com/uploads/carfront.jpg
There is a little bit of duct tape dangling down in the front, I was trying to make a better seal against the body of the car, but the gap was too large and the tape wouldn't stick. Also, there is a black pen line running across the front. I feel kind of stupid, but I was making a rough estimate mark for cutting and I didn't even realize I was drawing on the outside of the car.

http://www.antiyawn.com/uploads/carbottom.jpg
It's a pretty smooth surface. I had to cut away near the front wheels to make room for the tires to turn, but I didn't cut enough so it still scrapes. I'll go at it with a saw tomorrow.

http://www.antiyawn.com/uploads/carcorner.jpg
It's not exactly seamless. It was very hard to bend the material in three dimensions. I might go back over it with a heat gun and see if I can warp it to a better fit.

http://www.antiyawn.com/uploads/catconvert.jpg
I had to cut a hole for the catalytic converter, but the tailpipe itself is still a little too close to the plastic and it causes it to warp slightly. I will be lengthening this hole along the tailpipe in the future. I just have to find something to secure the edges of the hole to the frame.

Although it's not very easy to put these changes on and take them off, I plan on doing an A-B-A test as soon as my new scan-gauge is properly calibrated.

ch00f -

Wow, great stuff! I like your smiley license plate also, :D .

I hadn't specifically heard of the PVC sheets, (unless that is what they sell in Home Depot in the bath section?!?!?!). The Coroplast seems really hard to bend for smooth curves, so I tend to think of it as more of a belly-pan option. The PVC looks more useable for exterior "visible" mods.

CarloSW2

just to let you know, your water temp is probably causing your fan to kick in, which reduces your MPG because you're powering the fan through your alternator which gets power from the fuel. That's how it works in my 05 corolla and the 98's probably arent all that different.

Try purposely overheating your car over 200+ degrees and pop the hood and see if your fan isn't running....