Fox Body Mustang 5.0
 

Hi ive been lurking around this site for some time now...Ive done little things here and there...like weight reduction...removed A/c...tire pressures...underdrive pulleys...electric fan...shorty headers just to get better efficiency out my 91 Ford Mustang LX 5.0L

Im already looking at getting the MPGuino gauge, Vacuum gauge, more weight reduction, air tabs, grill block, advance timing, fix the cruise control..but i could basically take care of that with my foot. Possibly and electric water pump...kinda of pricey..and some 3.55 gears which after reading some it seems like those seem to get you better milage

Im shooting for a goal of 30mpg on the highway...since thats what i ussually drive.
Soon as i order my MPGuino and Vacuum gauge i will start taking note of my actual milage right now...im positive that my highway milage is around 25mpg right now...im not really to worried of not reaching that goal...i just need a way to actually keep track of my driving to keep me on check

Welcome. Sounds like your already on the right track.
Is your mustang a 5 speed or auto trans? Just looked Auto.
What gearing is in your axle?

I would only replace the water pump if you need a new 1 anyway otherwise it probably wouldn't be worth the cost.

Have you slowed down to the highway speed limit? I normally follow behind semis not tailgate because their speed limit is normally lower and their traveling slower anyways.

unfortunately its auto...Ive tried slowing down to the speed limit...but I currently need to fix my speedometer cable since its not actually hooked up so im going off engine RPM and GPS signal for speed...currently it has the stock 2.73 rear ratio I believe...or what ever stock is. I do try and keep a constant speed of 65 but at times i do creep to 70..i just gotta keep more alert...and of course there are those times when i like to do spirited driving :)

I do have some engines mods im doing soon...like an explorer intake manifold that both upper and lower have been ported...this should increase efficiency a bit

is the speedometer cable problem common my buddies stang i wanna say its 91 or 92 5.0 5 speed has the same problem.

if you have 2.73 then 3.55 would increase your rpms at highway speeds. I haven't dealt much with gearing but i believe lower is for top speed which would lower your rpms at the same speed

yes the speedo cable is very common and very easy to fix...i found one ebay for 12 bucks shipped new...just grease it up and throw it in...ive just been lazy and havent gotten around to it...lol...but one of these days ill get to...it involves pulling the instrument panel which takes like 10 mins do to and then route the cable...another 5 mins or so...and while u have the instrument panel out...might as well upgrade all the lights to LED so they wont burn out as quick...its like 18 of them i believe...the only ones that dont need changed are the battery bulb and check engine...the led does not have enough resistance to keep it off...you can find smd led lights for about 10 bucks for a 20 pack on ebay with 6smd led's per bulb...its a nice upgrade from stock. then put it all back together total time about 35-45 mins depending if u do the lights or not

yea i thought so too about the gearing being lower would increase mileage but there was an article i was reading earlier and it mentioned the 3.55 being better than the 2.73's

just looked it up 3.55 might be better for quarter miles times beings your acceleration would be better, but for fuel economy you want lower gear ratios.
Rear End Differential Gears Fuel Economy | MpgEnhance.com

And your gearing is probably 2.73

from 3.55 gear question

well in that case after reading that....i guess ill stick to 2.73 for now

I doubt any gains from electric water pump, for drag cars yes, but not for street cars. Drag cars it runs off the battery, street cars would run of alternator, so converting mechanical energy to electrical, then from electrical back to mechanical is inefficient.

Electric fans would be good since you've deleted the AC your fan is way oversized and at hwy speeds is not needed.

If you can fit some taller rear tires that will drop your HWY rpm's some, I'm sure you have plenty of torque to get them going, will throw the speedo off, but since it doesn't work anyway.

Air dam if you don't already have on.

If you want better highway, you'll want to deop it even firther. i have the 2.7s and replaced my 17s with 18s. Pick up tire size, and highway cruising becomes more fuel efficient(for the most part).

yes i got rid of the engine driven clutch fan that was stuck anyway...so i installed a complete stand alone unit with built in thermostat...between 180-220....would it be a good idea to turn the thermostat up to have the heat do more of the burning..i currently have it set to 180...i guess ill try that experiment out once i get the MPGuino to see if theres an actual difference...but on the highway it wont make a difference

yes im thinking of doing an air dam/grill block...havent really looked well into it...but i am thinking about it

He's right.
Even going up a size on the 15s will help.

See my threads in my signature.....
245/45/18 is stock
am running 245/50/18 on stock rim
went from 26" to 27.5" in diameter.
keeps my rpm low at highway speeds.:cool:

It will slow down your 'launches' but hey.......:thumbup:

dont need a vacuum gauge if your running the MOGuino

well i am running 225 55 16 i guess going a size up on the rears and leaving the front stock would not affect it too much...or do i need to swap all 4 tires for the taller size?

You want to swap the drive axle, so rears for you. And there is a terminal point where bigfer tires will be more harm than help, but i don't think a reasonable person will encounter that. If you do 16s front, 17/18 in back, you will help lower engine rpm, and create a low pressure zone under rhe rear of the care- more downforce, in theory, but that, in theory, means more drag.

Edit:
From my limited time on the site, mcrews knows his stuff. His guides are pretty good, and you might want to go his and my route and buy a more aero efficient front fascia. Just an idea.

yes im looking at getting a GT front or at least something to create the air dam

keep the stock gears because if you go to 3.55 you will get worse mileage on the highway....look into some aero mods, i'm sure for the mustang there are some front air dams that look good and divert the air from going under the car...or do a belly pan

yes im actually looking at mcrews belly pan right now...that thing is amazing

Couple of thoughts:
1. Need to do 40% or more of your driving at 'cruising speed' (55-65). some members are all city driving or only drive 5-10 miles a day.
2. Usually, if you stay in the same rim size you only add 1-3 lbs of static weight. Remember, that a spinning mass is 4x the static weight. so it is a 'little' harder to get going and a 'little' more wear on suspension parts when stopping.
3. if you go up a size in rim (15 to 16) then you are possiblly adding more weight AND that weight is moved farther out on the spinning circle. Then you have to add the tire weight which is also farther out.
4. You can probably get away with a larger rear rim. Higher end cars have sensors at each axle that are thrown off with different sizes.
5. Dont forget to air up your tires 40-45psi (see posts)
6. Also look at lower rolling resistance.
7. Finally, unless you are driving 20k or more, only replace tire size as your existing tires wear out. the cost of new tires BEFORE the old ones wear out wont paybvack in the increased mileage.

I took a lot of grief for running 'cheap' Kuhmos on the infiniti forum. BUt after 5 sets I have no regrets. Once you start driving smarter, you start driving easier. Everything lasts longer! And you dont need 'high performance' parts.

General Altimax HP

Went to tirerack.com and pick the General tire ONLY for SPECS.

225/55/16, 25.7" diameter, weight 22lbs, 9.2" tread width

225/65/16, 27.5" diameter, weight 25lbs 9" tread width

both fit the same rim.

You need to make sure the taller tire wont rub the bottom of the front strut mount. I think I post a pic on my thread showing how close mine was.

I have a soft spot in my heart for mustangs. My first car in 1975 was a 66 coupe w/straight 200ci 6cyl.

I also owned on of these w/ the 2.3liter turbo!


http://www.pjsautoworld.com/1970cars...gpacecar94.JPG

Last night I had to drive 75miles and I had less than a 1/4 tank I almost made it to my destination. I'm sure I could have made it...I was doing se serious drafting behind semis and I was driving between 55-65 most of the way. When I filled up last I wrote down 13.02 gallons and my mileage on my gps had a reading of 1,362. When I go back home today I'm going to try and drive the the same way and see how long this gas tank will last me driving the Eco way :)

Hi, I just joined up here because I am in a similar boat as you.
I installed a front air dam off of a late 80's ranger I bought for $5
I havent tested it yet but I think it cant hurt.
Beings I can't post links or images yet just google Brazeau racing mustang air dam and it will take you to a how to I followed.

p.s- I have a 84 GT and although it didnt fit 100% it was close enough and after some fine tuned trimming it looks decent

Wish I could see a picture that sounds intriguing

Brazeau Racing - Custom Front Air Dam
That looks nice...I was thinking of getting something that went from the front license plate down but that looks good. At least a quick option thanks for the info

Well after doing some upgrades and adding a vacuum gauge to my instrumentation i have gone from 18mpg combined to 23mpg combined...not bad :) def puts a smile on my face now to get some aero mods going and im still thinking about getting the mpguido gauge...

welcome!

I was getting 22mpg in my 89 LX 5 speed that was far from stock along with 3.73 gears. this was doing 65mph on a highway commute.

interested to see how you make out!

yea ive been thinking about getting 3.55 gears....just cuz i like to have some fun at times...i do plan on supercharging in the future

BTW I finally got around to fixing the speedometer...took me like 10 mins...while I was at it...I went ahead and installed a vacuum gauge that I found on ebay for 10 bucks. The lighting is Dim at night other than that it works great...ill probably put in an LED bulb in it later to match the rest of my dash

so much for your MPG goal :thumbup:

With forced induction and staying out of boost you actually do get better gas mileage than a naturally aspirated vehicle. That is after getting it properly tuned. So my goal is still not far fetched even with a supercharger..

Basically with forced induction the engine does less work since your force feeding all this air into it which when ur out of boost and like I said tuned properly...the car runs slightly leaner which in turn gets you better mileage...my old 2.2 cobalt after i turbocharged went from wAtever is stock mileage to 45mpg.. This was staying out of boost and driving normally... Now once I got to having fun in it mileage would drop to about 18mpg. Which would only happen on spirited driving on canyons or actually going to the track.

takes power to turn the supercharger
bigger injectors
safe fat tune

I'm subscribed :thumbup:

Well I already dropped in the bigger injectors... Basically she's all ready just for the bolt on... It does take power turn the supercharger but it really isn't that much as people think. Centrifulgal supercharges are very efficient unlike root style superchargers

your using 24's with the supercharger? how many pounds of boost you looking at?

Funny, my first car in 1975 was also a 66 coupe w/straight 200ci 6cyl.

Oh, there is a great website mostly dedicated to the 200ci six.

No supercharger yet but I plan on going with the vortech basic kit which is a 6-8psi kit

Awesome man welcome to the Forum. You'll get alotta slack about performance tuning for mileage but at te end of the day it's still your car. It's actually the motive behind alotta new muscle car builds. Older body styles for the look and styling and newer more advanced motors so you're still saving gas and running more efficiently. And I see you're from LA Maybe I'll see ya at one of the tracks around home some day

with 24# injectors?