Warburrito's eco / aero Protege5 build *new

2003 Protege5
So I recently picked up my second protg...a P5 wagon this time instead of an ES. My ES still runs at 247k miles but I hit the point where I'd rather drop the money for something in better condition instead of into the frequent repairs. After I strip any parts off of it that I want I'll be selling it to my buddy.

This build will most likely bore most as my goals are not grand or typical. I want to get the best mpg possible while maintaining or improving existing performance, comfort, and dependability levels as it will be my daily driver. I realize that is pretty much asking for everything, but I figure I will be sacrificing in the weight reduction department. So no complete gutting of the interior to save weight, in fact I may even add a small sub, sound deadening, and aero mods that will ADD some weight. I will mostly focus on engine efficiency and aero mods with occasional suspension and interior mods thrown in. In the end it may look like I'm trying to turn it into a race car combined with a big rig, but I don't care. I'll have a car that'll be FUN to drive and CHEAP to operate. I enjoy saving money (Go Dave Ramsey!), I enjoy driving my Mazda, and I enjoy solving problems creatively so this should be fun.

Any recommendations on unnecessary items I can remove that won't effect comfort would be appreciated...brackets for baby seats are a good example of what I WOULD remove.

I have a few requirements...I want to stay with 87 octane fuel, I have 3 kids so I can't sacrifice space in the back for them, and I mountain bike, windsurf, and kayak so the roof racks will have to stay...hopefully the factory ones for aero benefits over the Yakima rack from my ES.

My goal is 40mpg...which is approximately $602 dollars saved in annual fuel costs. I don't want to spend more than I would save in annual mpg improvements and I have yet to determine exactly how that equation would look, but here goes... I work 25 miles from my house, so I drive 13000 miles a year just going to work and back. I'm going to estimate 20,000 miles a year total. At $2.50/gal for 87 octane, if I go from 27 to 35mpg I would save ~$423 dollars annually, another $179 at 40mpg, another $139 at 45mpg, and another $111 at 50mpg. Since the first few improvements in gas mileage will save me the most money and will probably cost less than moving from say 45 to 50 mpg, I am tentatively setting a goal of 40mpg. That would save me $602 dollars a year in fuel costs. I will not be counting regular maintenance costs like engine oil changes and air filters as I would have to budget for those anyway.

Economy Upgrades Completed:
-Stage 1 air intake (Goldstar) -free
-NGK V-Power ZFR5F-11 plugs (long reach) -maintenance
-Valvoline High Mileage 5w30 full synthetic oil -maintenance
-Seafoam intake, crankcase, and fuel - maintenance
-EGR valve cleaned - maintenance
-Torque app and ELM 327 BT OBD2 adapter -$11
-STI s204 PU front lip -$46
-Stolspeed VGs (vortex generators) - $68
-Honda stubby antennae -$12
-body panel gap filling - $14
-Duralast Flex blade wipers -maintenance
-Weight reductions: child seat brackets, oh s**t handles -free

Economy Upgrades to Consider: (most likely to least likely) (please mention any others that I should consider)
-unnecessary weight reductions (SUGGESTIONS would really be helpful here)
-lowering car
-Stagg SHS shock/struts -maintenance ($165)
-Tein S Tech springs, 1.8"f/1.5"r -$183
-IM replacement with port/polish, VTCS removal, and deep cleaning
-IM out of 2001 ES (free)
-Hydra Motorsports thermal intake gaskets ($30)
-new silicone vacuum hoses ($)
-Motorcraft MTX-75 synthetic manual transmission fluid
-ground wire upgrades - 1sty Ground Wire kit from mazda247
-additional intake mods (Soarer BFI and Simota Aero inspired) (egg holders $13)
-Improve seal in area between hood and windshield
-partial grille block
-HDPE underbody panels, 1/8 inch (front, middle, and rear diffuser)
-considered coroplast but I think HDPE will be more rigid and require less aluminum reinforcement
-wheel arch gap filling (front and top)
-wheel well venting towards rear / boat-tailing behind tires
-plexi or lexan over fogs
-OBX or 4-2-1 Probe headers (economy and saves 18 lbs)
-Split Second AFC
-one for sale in Indy for $200 used
-626 final gear
-motorcycle/F1 style rear view mirrors
-rear corner airflow trip feature
-cruise control mods - [/url]http://ecomodder.com/forum/showthread.php/cruise-control-mpg-sensitive-logic-2031.html[/url]
-synthetic axle / wheel bearing lube
-Hydra lightweight crank pulley (same as stock, but 4lbs lighter)
-shaved door handles
-lexan rear windows
-plexi removable boat tail
-softened / radiused aft edge of front wheel arches and gap minimizing
-lighter weight rims / wheels (probably cost restrictive)
-lightweight flywheel (probably cost and skill level restrictive)

Economy Upgrades Ruled Out:
X MP3 ECU (want to keep 87 octane fuel)
X NON-Ethanol fuel (cost prohibitive and scarce, GREAT OPTION otherwise)
X catback exhaust (I like quiet)
X roof rack delete (need for hauling fun outdoor toys)
X flat wheel covers (too ugly)
X spare tire and tool removal (I live in extreme pothole country and have needed these many times)
X regenerative braking (probably cost restrictive)

Other Upgrades Completed:
-Purolator One PL14610 (Mazda 626) oil filter
-Purolator A25049 air filter
-Mazda 6 front brakes (2005)
-Magnum Brakes SS braided brake lines
-NAPA Premium front rotors
-Duralast Gold ceramic brake pads
-Goodridge SS braided clutch line
-Lucas Oil Synthetic DOT4 brake fluid
-Philips LL EcoVision H7 bulbs
-LED T10 backup light
-Kuat Dirtbag 20mm bike fork holder
-Dupli-Color BGM0522 Storm Grey Metallic accents
-Hydra Motorsports cluster rings
-Tungsten weighted OEM shift knob (317g)
-Frost King sound deadening in doors
-Pyle PLG6C rear component speakers
-Subaru Forester overhead console
-Mazda2 AC Knobs
-AC flickering fix

TORQUE APP AND ELM327 BT OBD2 adapter - $11

If I was going to improve my mpg I need to learn to drive more efficiently and track any progress. These 2 items cost me $11 total and work well. Sometimes it takes a while to connect, and sometimes the vacuum gauge doesn't give a readout, but for the cost I'm happy. EDIT: If you are in the market purchase the ELM327 from Ebay that is thinner with a curved top, the larger boxier version has a lot of trouble connecting.


I decided that Goldstar's intake mods to the OEM air intake would be my "stage 1" air intake. I had a custom CAI on my ES and wasn't impressed with the mpg. It did improve high RPM power and sounded great, but the mpg loss wasn't worth it. I opened up the top portion of the grille, duct taped over all 6 holes, sealed connections, and removed the grate before the MAF. I did notice a slight increase in mid range power, a more throaty sound, and an increase in mpg, but at this point some of that could be learning to drive more efficiently by using the Torque app and adjusting my driving style a little. At this point I've gone from averaging ~27.5mpg to averaging ~29mpg. *****EDIT: I later modified the MAF waffle grate thingy and reinstalled it and noticed a pretty sizeable MPG gain. Better description in post #8


Compared to my ES this thing is LOUD inside. I realize that this is mostly due to the Firestone Firehawk AS tires, but I had to do something about it. Neither of the front door lock actuators were working when I got the car and the rear passenger's side speaker wasn't working so I thought I could address all of these things at the same time. I decided on Frost King duct insulation, Pyle PLG6C component speakers, and took the actuators out of my ES. I downloaded Sound Meter on my LG G3 and my interior noise at 60mph on a calm day went from 70 dBA to ***** after covering all 4 doors. I plan on doing the trunk as well, but will probably wait until I purchase an MX6 rear strut bar and do those 2 things at the same time.


I probably should have done these separately but I can't make a $17 purchase and not install it. Wires looked good so the swap was easy. I've definitely noticed a difference in mid range engine torque. I'm up to over 30mpg but I've only filled up once since.

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Jackie chan

Team Pro5
Sweet, will be watching. S204 lip isn't really low enough to be effective. I'd go with the lawn edging lip. It won't look as good, but it'll take a beating and be very effective as an air dam. And can be done for a few bucks.
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2003 Protege5
So you think the s204 lip will be low enough to match the sideskirt height? Since I'll be doing an underbody tray that's what I was going for.
2003 Protege5
So I filled up yesterday and got the worst mileage yet...25.87. It's very very hot and humid so I've been running the AC a lot, but I think the main culprit is dragging rear brakes. Occasionally I've noticed when I brake or take a corner my parking brake light will come in until I accelerate again. Also, when I set my parking brake there is almost no resistance when pulling up. I need to research the best solution to this and hopefully work on it this weekend.


2011 MX5 GT
Sorry to be a negative nancy, but there is no way you will get ~40 mpg with a roof rack and all that extra sound deadening weight added to the car. For high mileage, you want the least amount of wind resistance and the lightest weight you can achieve. You need to remove as much weight as feasible, make the car as slippery as possible, and make the engine breath as easy as it can; none of which you have yet done.

I applaud your desire, but I am not sure you are going about it just right.
2003 Protege5
I understand that people will feel that way and completely AGREE that weight savings is a great if not the best way of increasing mpg. I'm going a different route and would like to see what I can achieve anyways.

Sent from my VS985 4G using Tapatalk
2003 Protege5
So I had previously removed the MAF screen per Goldstar's intake instructions, but got thinking about it and decided to gut the screen everywhere except the center, so that air flows around the sensor more freely than over the sensor. It should also decrease turbulence over the sensor and get better readings. Theoretically this should make my engine run slightly leaner and increase FE. If it leans it out too much I should throw a CEL from the O2 sensors readings and I can just go back to having it removed. On my 25 mile commute to work this morning my Torque trip mpg was 38.8...a big improvement over my current average of 34.1 in Torque. Again, this doesn't monitor idling and I idle a lot a lunch lately.

2003 Protege5

I considered many front lips and air dams, but decided on the S204 polyurethane lip since I wanted the flexibility, a clean sharp edge, and didn't care to go super low since I will be making underbody panels. I decided to keep the higher section in the middle and use 1/4" Nylon spacers on the screws after that section, keeping the front pretty even all the way across. I did not space out the back so it would be closer to flat instead of following the original lines back to the tire. I then filled in the small gaps with black 3/8" closed-cell foam. I'm considering changing that out for black Gorilla Tape for a smoother finish, but we'll see. The front now sits at least as low as the side skirts. It could be all mental but it feels like the car has less lift at highway speeds now because the suspension feels more solid over crappy Indiana highway bumps and small potholes (I swerve all over the road to avoid big potholes and bumps and creep over railroads and metal road construction plates. Thank you shoulders, curb-less roads , and oncoming traffic lanes).


Purely cosmetic, but I like the way they look. I had to trim down the width of the knobs for them to fit correctly. I also pushed the fan speed knob in too hard and it dislodged the rear of the dial. I'm still figuring out how to tighten it back up, but it is still working and looks normal, it just gets sloppy when you turn the dial.

Additional Updates:

I altered some settings within Torque and now the MPG calculation includes idle time. While its sad to see the reduction in MPG it now more closely coincides with my actual measuring at fill-ups, so it’s a good thing. I also removed all oh s**t handles and unused child seat brackets to save weight. For about 2 weeks I was receiving occasional CELs after my MAF waffle grate mod for "engine running too lean" but no pinging. Each time I'd reset it through Torque I would go about 2 days before it would come on again. It has now been about 3 weeks with no CELs so I think the ECU just got used to it. Time will tell.
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2002 Mazda Protege5
You'd need to calculate whether or not this is cost effective in your area but I've seen consistent gains of 10% in fuel economy when using NON Ethanol gas.
2003 Protege5

I evenly distributed a can of Seafoam in the brake booster, fuel tank, and crankcase about 200 miles before changing the oil. I switched the oil to Valvoline High Mileage 5w30 full synthetic from Valvoline Max Life 5W30 synthetic blend. I used a Purolator One PL14612 oil filter but will get the PL14610 from the 626 V6 next time as it is larger. I was about half a quart low after 5k miles at this change, so if I'm much lower than that at the next change I'll go back to using the blend. This thing is still running great with more power, less valve chatter, and smoother than my ES was at around the same mileage, so I'm going to stick with Valvoline since that's what has always been used in this P5.


While I still have more to do, most have been filled with some form of closed cell rubber foam. The D-shape rubber stuff is my favorite and I was able to use it on the hood, grille, and parts of the door and rear hatch gaps. I used various heights of rectangular foam rubber on the upper front door areas. I'm still looking for some quality flat rubber to fill in where the front door hinges are and the top of the rear hatch.

Additional Updates:

I ordered a different Bluetooth OBDII adapter hoping to correct my connection issues and it works flawlessly now! For those of you in the market make sure to order the ELM327 OBDII Mini unit that is smaller and has a rounded top, not the boxier version with a flat top.

Thank you dbgrubbs for the suggestion on running non-ethanol fuel! After some research I found that the closest gas station that sells it is a CountryMark in Lebanon that is 15-20 minutes away. The 87 octane regular fuel was $1.88 while the 91 octane Ethanol Free fuel was $2.75. 91 is their only ethanol-free option. There is a CountryMark closer to me that does not carry ethanol-free fuel but are "considering" bringing it to that station in the future according to the manager. I can't imagine the fuel savings being worth the cost difference at this point even if it was right by my house.

I'd like to upgrade to synthetic MT oil soon but I am torn between Motorcraft MTX-75, Pennzoil Synchromesh, and Redline MT90 and can't make a decision. Posts like http://www.mazdas247.com/forum/showthread.php?t=123855732 should help but don't really seem to give a definitive answer. Any help would be appreciated either here or in that post as I'll see either.

My rear passengers side strut blew through my strut tower mount. Pretty standard really… it happened several times on my ES, but man I hate that sound! I replaced with a Napa part for $30 and its good to go … except I now have a mild, almost muffled clunking sound when going over small cracks in the road. I posted a question about it on the forum looking for some help but have not had any replies yet…http://www.mazdas247.com/forum/showthread.php?t=123856444.

Stolspeed VGs are partially installed...update coming later this week.
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2003 Protege5

After reading endless posts about VGs (vortex generators) I decided to go with separate opposing micro VGs from Stolspeed. $68 shipped from aircraftspruce.com for 80 pieces seemed steep at first but compared to the 10packs on eBay for around $30 they are affordable and a much better design. There are many good options available like Airtabs, turbulator tape, and dimpled Dymo tape, but I chose Stolspeed VGs because...
-they can be arranged as opposing VGs so the vortices won't collide
-they can be placed separately instead of paired together
-they can be placed at an optimal 15-20 degree angle
-they have reduced surface area and drag compared to most
-the mounting edges and top are rounded and smooth
-they are flexible
-they are UV resistant
-they are clear but paintable

VGs are best placed within ~10 inches of any trailing edge and/or directly before the separation layer begins to form on the surface. This layer can be found with tufting using tape and yarn while driving. I couldn't clearly identify the separation layer from the testing on my roof so I decided to just place them within 10 inches of the rear of the car, prior to any rear curvatures. I started in the center of the top of my car and worked my way out and down the sides. I will also be placing them before the front and rear wheels this weekend. After my underbody tray is in place I will likely place them prior to any gaps and the diffuser and a row on the underside of the front lip. I found that snap/lock-ring pliers worked well for getting the air bubbles out of the adhesive, although the results still weren't perfect. Stolspeed VGs have a slightly concave bottom to better match the curve of airplane wings and that makes getting the bubbles out on flat surfaces difficult. I tried soapy water but unless it was almost completely wiped off the adhesive would not stick properly. I know I should have done some A-B-A or A-B coast testing, but weather conditions kept changing here so I went ahead and installed them. I'll give an update on MPG and feel soon.

The links below contain some of the best information I found while researching VGs, but there is a ton out there on the "Interwebs"

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2003 Protege5

I removed my EGR valve, disassembled it, and cleaned it with brake cleaner and a small round file, and added lube according to the writeup here - http://www.mazdas247.com/forum/show...o-EGR-Removal-and-Cleaning-for-Rough-Idle-Fix. It was pretty dirty inside but was not seized up. The brake cleaner did not get it back to shiny new condition but it did allow me to remove most of the soot build up. While I had my intake tube off I glanced inside the throttle body and saw a hefty amount of black, oily soot-like buildup in there as well. I added that to my to-do list as the Seafoam treatment through the brake booster line obviously did not handle all areas. When searching for the best way to clean the intake manifold I found that certain 2003 Protege5 have a recall on the EGR valve and IM so I called a dealership but mine does not have any open recalls. Looks like I will probably buy a used IM, clean it out, do some porting and polishing, and delete the VTCS system. If anyone has an IM available please let me know.

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2003 Protege5

I added some additional VGs prior to each wheel. I made sure to angle the highest one to direct air in a swirl away from the top lip of the wheel well...otherwise it would swirl more air into the wheel well and hurt FE. The line along the back of the car has seemed to increase my MPG slightly from an average just below 30 from mid August through early September up to 32.57 on this last tank. Prior to this tank I had not seen numbers over 30.23 outside of strictly highway miles. I know that is only one tank but it is enough to convince me they are not hurting my FE and encourage me to install more. I have not noticed any difference in the way my car drives.

Additional Updates:

To hold me over until I purchase a new IM I have been using a small spray bottle to get Seafoam into the throttle body with the intake tube removed. I'll do it after the engine is already warm, hold the throttle open, spray, let it sit for 10 minutes, then run the car.

I'm still looking for assistance with the questions below...

I'd like to upgrade to synthetic MT oil soon but I am torn between Motorcraft MTX-75, Pennzoil Synchromesh, and Redline MT90 and can't make a decision. Posts like http://www.mazdas247.com/forum/showthread.php?t=123855732 should help but don't really seem to give a definitive answer. Any help would be appreciated either here or in that post as I'll see either.

My rear passengers side strut blew through my strut tower mount. Pretty standard really… it happened several times on my ES, but man I hate that sound! I replaced with a Napa part for $30 and its good to go … except I now have a mild, almost muffled clunking sound when going over small cracks in the road. I posted a question about it on the forum looking for some help but have not had any replies yet…http://www.mazdas247.com/forum/showthread.php?t=123856444.
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(u_u) ...zZzZzzz
the pennzoil is pretty good and convenient since it's available at the store for me. between the redline mt90 and pennzoil synchromesh, the redline shifted smoother to me. this is on my msp where it has a short shifter and shift linkage bushings making it super duper notchy.


(u_u) ...zZzZzzz
no problem. don't get me wrong, im currently running the pennzoil on the msp and it's fine. i will do the same for the beater p5 when i get to it just because i dont have to order it online.