20+ mpg is it possible???

Patrick Boetticher · 07-23-2002, 02:11 PM

ok im sick of this 12-15 MPG the last tank i got a whoping 9.8 MPG now assuming that was a fluke (this is all HW no traffic) im still averaging about 14 MPG my ultimate goal is above 20 untill i hit that im not gonna put in my 3.55s!!! i need some help... i replaced my O2 sensors im putting in a new distributor today and well see how it does... ANY HELP WOULD BE GREAT driving close to 125 miles a day is killing me...

Skyman · 07-23-2002, 03:46 PM

Mine gets 21-22 freeway, I havn't checked intown.

Skyler

lx mike · 07-23-2002, 04:50 PM

I have 3.73's and i get about the same as skyman my engine is basicly stock ( heads cam and headers) have cobra intake and t.b and bigger mass air but thats all. I drive around 70-75 on the highway. what does the air fuel gauge show when running at speed?? what fuel pressure??

91GTturbo · 07-23-2002, 05:28 PM

You've got a heads and cam mustang and your asking about gas mileage

. Sorry to sound harsh, but buy a beater and save the mustang for the weekends. I can't have much sympathy for anyone who gets into performance cars and then complains about gas mileage.

Comatose · 07-23-2002, 06:44 PM

I average 17-19 in town and 22-25 highway.

Maroon 5.0 LX · 07-23-2002, 08:38 PM

With all the modifications to your engine, I'm surprised you get the milage you do. Your poor 'ole engine has so many changes, it doesn't know what to do...

My stock '89 gets 19 around town, and 26 on the road.

Dog5ohfun · 07-23-2002, 09:11 PM

I have a 306 with head work, cam, full exhaust 24# injectors and I get 18 around town and 24mpg on the freeway. Check to see if your mass air meter is calibrated for your 19# injectors. Your fuel pressure is way to high, mine is about 38psi and it still might be high. Start with it set at 36psi. Also I would check on the availability of getting your car put on a dynomometer. That would help with tuning it. Your fuel pressure is to high and your computer is trying to lean the motor. Start with turning it down. Good luck. I bought a Focus so I didn't have to worry about the Mustang for commuting to college, 700+ miles round trip. $26 in the Focus as apposed to $80 or so in the Mustang. Again good luck.

Brent

Skyman · 07-23-2002, 10:05 PM

These people bitching dont know what theyre talking about.

A mustang with your mods should get 20-24mph on the freeway around 70mph. Something is definatly wrong with your car. Im sorry I dunno what it is, but good luck buddy.

Skyler

Godslayer · 07-23-2002, 10:12 PM

I have to disagree Skyman. I have a completely stock 86GT/t-5 in good condition and I only get about 16/21. The car runs great and it has a fresh motor with 20k.

I can't imagine his car getting more than 13/18 with his mods. Added he has a hefty amount of stereo equipment and other weight.

briand · 07-24-2002, 07:50 AM

skyman i definatley agree with you buddy, i have all the stuff like aluminum heads, intake, cam, and so and i also get 20mpg with the mix of highway and city driving, so it is not uncommon to get good gas mileage with these modified cars, the eec-iv is great at adapting to modifications, i would check every tune up part and maybe check that fuel pressure 42 psi sounds kind of high with your modifications. well i hope you get this thing solve, man. and don't settle for the gas mileage you have, more mpg can be found. oh, also check your codes. take it easy

jimberg · 07-24-2002, 08:01 AM

I get a pretty rock solid 19mpg. You can look at my Users' Ride listing to see my mods. My guess would be that your computer is stuck in open loop mode and you are always running rich because of it. Take it to a Mustang Dyno that has a wide band oxygen sensor and do some testing. Verify that all your sensors are working properly. MAF, ACT, ECT, BAP, O2 and EVP. Those all help determine A/F ratio.

Lethal5Oh · 07-24-2002, 01:38 PM

How do you drive? When you get on the highway or from a stop do you accelerate quickly? Do you wait to the last minute to let off the gas and start braking when coming to a stop? Ive found that letting the car coast when im coming to a stop and accelerating easily not heavily i get better mileage. Best ive gotten (mostly stock stang granted) is 20 with half of the tank being used on the highway and the other used around town. Havent yet to get a solid highway number. Driving better wont get you 20 MPGs but it will help get you there. Good Luck

86GT · 07-24-2002, 02:34 PM

I average 20-22 mpg on highway, and around 15 mpg in town, that's taking it easy of course. If I drive it like I stole it then its terrible on gas. It's worth noting that when I went from stock to my current setup I gained a few mpg. Guess all the free flowing parts help (keep in mind that driving style may have a lot to do with it). Check the usual culprits: Tune Up, Fuel Filter, Injectors, pump, MAS, Timing and Fuel Pressure.

jimberg · 07-24-2002, 02:47 PM

Check your fuel pressure regulator with one of those hand vacuum pumps. Turn your ignition to the on position but don't start the car. Jumper the fuel pump test lead on your test harness to ground. Fuel pressure should be at 42. Slowly apply vacuum. The fuel pressure should drop as you increase vacuum. If it doesn't, your regulator is shot.

Hethj7 · 07-24-2002, 03:06 PM

Sky is all over this one and knows what he is talking about.
After getting my Stang properly tuned on a dyno, I have seen as high as 29 mpg on the hi-way (and yes, my speedo is accurate and I know how to figure gas mileage).

It is rare that I see it that high, but I can always get 24-25 out of it on the hi-way. This is with heads, cam, intake, and all the goodies that go along with them.

I am not sure what would be causing your poor mileage, Patrick, but you can definitely get better than what you are.

Chris_H · 07-24-2002, 09:07 PM

Just figured I would throw my $.02 worth in. I have seen as good as 25mph on the highway, and as bad as 12 mpg on the highway. Like everyone else has said, it all has to do with your driving habits. I find that when I am not the first one through the intersection like I am at the tree, and when I take my time getting places (5-10mph over) I can usually get pretty good gas mileage on a tank. I drive on average 40 miles roundtrip to work and back through construction all the way, and to school, another 25 miles a day, and I cand average about 18-20mpg. I just need to curb my driving habits from time to time, but like this tank, I have gone 150 miles and down to 1/4 tank already. Just depends on how you drive.

Chris

Patrick Boetticher · 07-24-2002, 10:54 PM

Thanks so much for the help i didnt think id get this many replys but a huge thanks for your suppot!!!

-The injectors are calibrated for the meter (all stock) i know thats holding me back... i have a new EEC, and meter no injectors. though. cant afford them GAS IS KILLING ME...

-Im Gonna check the coil too and the ingition module...

-New distributor makes the car run so much better!!! smother and all!!! i still get a large stumble (feels like a rev limiter) if i put my foot into it at all. espesially abouve 4000. but if i keep it nice and Real slow its fine. did that before the new one too...

-Ok 42 PSI ok ill check that!!!

-Check codes left bank O2 reads rich and right bank O2 reads lean. im replacing them tomarrow!!! no more codes...

I do get on it dont get me wrong!!! But im talking all Highway.
-As for the driving habbits no matter who drives the car it gets bad MPG dad, mom, friends ect... soooo im usually pretty good in my dads car i get good MPG, Around 23-24, its a 2000 GT. the highway driving i do is " Put it in 5th AND GO 80" its like 90-100 miles round trip... no traffic usually.

- ECT, BAP, and EVP. these were the only ones i cant figure out...

-That A/F gauge dosent do $%!* it is the biggest POS. it makes the car sputter and couph when its hooked up!!! I think its broke though. It is hooked up right cuz it hasent always done that.. but it has never read anything worth while to me... its $49.00 light show!!!

Patrick Boetticher · 07-25-2002, 12:36 PM

ok did some test out of my shop manual evertyhing checks out good exept the coil....and the 02 sensors but thats getting replacesd... thanks for alll the help... illkeep you updated

Lethal5Oh · 07-25-2002, 10:46 PM

If your going to replace your coil check out this site www.performancedistributors.com I just got their kit in the mail and its real nice. Have started the car yet because i have a few things to do. check it out.

nickj8685 · 07-26-2002, 10:17 PM

If I could get 20mpg out of my car I would be happy. I usually get 14-16mpg. And it is pretty much stock. But then again I'm running a carb and not efi.

07-23-2002, 02:11 PM	#1
Patrick Boetticher Registered Member Join Date: Feb 1999 Location: Camarillo/Thousand Oaks Ca Posts: 223	20+ mpg is it possible??? ok im sick of this 12-15 MPG the last tank i got a whoping 9.8 MPG now assuming that was a fluke (this is all HW no traffic) im still averaging about 14 MPG my ultimate goal is above 20 untill i hit that im not gonna put in my 3.55s!!! i need some help... i replaced my O2 sensors im putting in a new distributor today and well see how it does... ANY HELP WOULD BE GREAT driving close to 125 miles a day is killing me... __________________ Mustang Sold 2003 Ranger Edge

07-23-2002, 03:46 PM	#2
Skyman I need 110mph Trap Speed! Join Date: Feb 1999 Location: So, CA Posts: 4,315	Mine gets 21-22 freeway, I havn't checked intown. Skyler __________________ 2001 BMW M3 6spd 12.79@108 RIP ---- 1993 Notch w/ 98 4V 4.6 Fasttt... -1989 Saleen Mustang #406- 12.32@109 -1999 Black Cobra Coupe- JBA Shorties, Bassani Cat-X, Magnaflow 3", Pulleys, 85mm Pro-M, Ported Intake, Soild Rear w/ 4.30s, Tubular Front End, X2C arms, 13lb batt, few others.

07-23-2002, 04:50 PM	#3
lx mike Undescribable Join Date: Sep 1998 Location: Ft Myers Fla Posts: 1,539	I have 3.73's and i get about the same as skyman my engine is basicly stock ( heads cam and headers) have cobra intake and t.b and bigger mass air but thats all. I drive around 70-75 on the highway. what does the air fuel gauge show when running at speed?? what fuel pressure?? __________________ Rice Haters Club Member #101

07-23-2002, 05:28 PM	#4
91GTturbo Registered Member Join Date: May 2001 Location: Valdese, NC Posts: 361	You've got a heads and cam mustang and your asking about gas mileage . Sorry to sound harsh, but buy a beater and save the mustang for the weekends. I can't have much sympathy for anyone who gets into performance cars and then complains about gas mileage. __________________ 91 single turbo vert

07-23-2002, 06:44 PM	#5
Comatose Registered Member Join Date: Oct 2001 Location: Goldendale, WA, USA Posts: 84	I average 17-19 in town and 22-25 highway. __________________ Jeremiah 1986 Mustang GT K&N Filter, Removed Air Silencer, Black Magic Fan, 65mm Explorer TB, 110lph BBK Fuel Pump, F/M Force II Cat -Back, O/R h-pipe, U/D's Timing@14* 1986 Mustang LX SSP--new project car AOD, 3.27's, Dumps, 238k miles

07-23-2002, 08:38 PM	#6
Maroon 5.0 LX Registered Member Join Date: Mar 2001 Location: Southern Maryland Posts: 471	With all the modifications to your engine, I'm surprised you get the milage you do. Your poor 'ole engine has so many changes, it doesn't know what to do... My stock '89 gets 19 around town, and 26 on the road. __________________ '89 LX 5.0 - 5 speed. Original Owner '94 E-150 4.9 Hi-Top Conversion Van '06 Mustang V-6, 5 speed

07-23-2002, 09:11 PM	#7
Dog5ohfun Registered Member Join Date: Feb 2002 Location: Arlington, Washington Posts: 92	I have a 306 with head work, cam, full exhaust 24# injectors and I get 18 around town and 24mpg on the freeway. Check to see if your mass air meter is calibrated for your 19# injectors. Your fuel pressure is way to high, mine is about 38psi and it still might be high. Start with it set at 36psi. Also I would check on the availability of getting your car put on a dynomometer. That would help with tuning it. Your fuel pressure is to high and your computer is trying to lean the motor. Start with turning it down. Good luck. I bought a Focus so I didn't have to worry about the Mustang for commuting to college, 700+ miles round trip. $26 in the Focus as apposed to $80 or so in the Mustang. Again good luck. Brent __________________ Black 1990 LX DSS Racing Super Pro Bullit 331, AFR 185, Anderson B31 Cam, 1.6 DSS rockers, Cobra Intake w/ 2 phenolic spacer, Aluminum DS, 3.73 gears, Tremec 3550, Lakewood SFI Bellhousing, MSD Digital 6+, Spintech Side Exhaust,

07-23-2002, 10:05 PM	#8
Skyman I need 110mph Trap Speed! Join Date: Feb 1999 Location: So, CA Posts: 4,315	These people bitching dont know what theyre talking about. A mustang with your mods should get 20-24mph on the freeway around 70mph. Something is definatly wrong with your car. Im sorry I dunno what it is, but good luck buddy. Skyler __________________ 2001 BMW M3 6spd 12.79@108 RIP ---- 1993 Notch w/ 98 4V 4.6 Fasttt... -1989 Saleen Mustang #406- 12.32@109 -1999 Black Cobra Coupe- JBA Shorties, Bassani Cat-X, Magnaflow 3", Pulleys, 85mm Pro-M, Ported Intake, Soild Rear w/ 4.30s, Tubular Front End, X2C arms, 13lb batt, few others.

07-23-2002, 10:12 PM	#9
Godslayer Registered Member Join Date: Mar 1999 Location: Largo, FL USA Posts: 274	Hmm.... I have to disagree Skyman. I have a completely stock 86GT/t-5 in good condition and I only get about 16/21. The car runs great and it has a fresh motor with 20k. I can't imagine his car getting more than 13/18 with his mods. Added he has a hefty amount of stereo equipment and other weight. __________________ Negative Mustang @ present time.

07-24-2002, 07:50 AM	#10
briand Registered Member Join Date: Mar 1999 Location: Jackson, LA Posts: 264	skyman i definatley agree with you buddy, i have all the stuff like aluminum heads, intake, cam, and so and i also get 20mpg with the mix of highway and city driving, so it is not uncommon to get good gas mileage with these modified cars, the eec-iv is great at adapting to modifications, i would check every tune up part and maybe check that fuel pressure 42 psi sounds kind of high with your modifications. well i hope you get this thing solve, man. and don't settle for the gas mileage you have, more mpg can be found. oh, also check your codes. take it easy __________________ GT-40X heads(58cc), Cobra upper and lower, 75 mm Bullet, Moroso fenderwell induction, FRPP 65mm TB, 24# injectors, black magic electric fan, phenolic spacer, 1.7 crane cobra roller rockers, crane 2031, BBK 1 5/8 equal length hearders, 2.5 inch off road pipe, 2.5 flowmaster catback, FMS 3.55 gears, T5-Z transmission, FRPP aluminum driveshaft, svo heavy duty clutch, mcleod bullet proff bellhousing, BBK adjustable cluth quadrant, hurst billet shifter, lakewood subframes, BBK strut tower brace, BBK 2pt lower cross bar, FMS 190 lph fuel pump, crane ps91 coil, FMS street pulleys, and 300+ race wires. All thanks goes to my wife sheri, jason, jeff, robby, my dad and all others you helped contribute. most importantly GOD!!!

07-24-2002, 08:01 AM	#11
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	I get a pretty rock solid 19mpg. You can look at my Users' Ride listing to see my mods. My guess would be that your computer is stuck in open loop mode and you are always running rich because of it. Take it to a Mustang Dyno that has a wide band oxygen sensor and do some testing. Verify that all your sensors are working properly. MAF, ACT, ECT, BAP, O2 and EVP. Those all help determine A/F ratio. __________________ 351W 89 Mustang GT Convertible Last edited by jimberg; 07-24-2002 at 01:40 PM..

07-24-2002, 01:38 PM	#12
Lethal5Oh Registered Member Join Date: Jun 2002 Location: Portage Posts: 239	How do you drive? When you get on the highway or from a stop do you accelerate quickly? Do you wait to the last minute to let off the gas and start braking when coming to a stop? Ive found that letting the car coast when im coming to a stop and accelerating easily not heavily i get better mileage. Best ive gotten (mostly stock stang granted) is 20 with half of the tank being used on the highway and the other used around town. Havent yet to get a solid highway number. Driving better wont get you 20 MPGs but it will help get you there. Good Luck __________________ '95 GT convert. K&N, C&L mass air meter, Performance distributors sreamin demon coil, dyna mod, live wires, king cobra clutch, flowmaster american thunder exhaust, UPR billet adjustable shift handle, Crane Cams Fireball HI-6 box,underdrive pullies, 255lph fuel pump, UPr short throw shifter, caster camber plates, 03 cobra lower A arms, bullit suspension, cobra front brakes

07-24-2002, 02:34 PM	#13
86GT Sniffed too much n20 Join Date: Oct 1998 Location: Ont, Canada Posts: 1,018	I average 20-22 mpg on highway, and around 15 mpg in town, that's taking it easy of course. If I drive it like I stole it then its terrible on gas. It's worth noting that when I went from stock to my current setup I gained a few mpg. Guess all the free flowing parts help (keep in mind that driving style may have a lot to do with it). Check the usual culprits: Tune Up, Fuel Filter, Injectors, pump, MAS, Timing and Fuel Pressure.

07-24-2002, 02:47 PM	#14
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	Check your fuel pressure regulator with one of those hand vacuum pumps. Turn your ignition to the on position but don't start the car. Jumper the fuel pump test lead on your test harness to ground. Fuel pressure should be at 42. Slowly apply vacuum. The fuel pressure should drop as you increase vacuum. If it doesn't, your regulator is shot. __________________ 351W 89 Mustang GT Convertible

07-24-2002, 03:06 PM	#15
Hethj7 Mizzou Tigers Join Date: Apr 1999 Location: weston, MO United States Posts: 1,455	Listen to Sky! Sky is all over this one and knows what he is talking about. After getting my Stang properly tuned on a dyno, I have seen as high as 29 mpg on the hi-way (and yes, my speedo is accurate and I know how to figure gas mileage). It is rare that I see it that high, but I can always get 24-25 out of it on the hi-way. This is with heads, cam, intake, and all the goodies that go along with them. I am not sure what would be causing your poor mileage, Patrick, but you can definitely get better than what you are. __________________ 2006 Mustang GT 1990 LX GT-40 motor 262 horsepower, 307ft-lbs (sold but forever loved) 1998 Contour SVT Rice Haters Club Member #244

07-24-2002, 09:07 PM	#16
Chris_H Registered Member Join Date: Oct 1999 Location: New Mexico Posts: 488	Just figured I would throw my $.02 worth in. I have seen as good as 25mph on the highway, and as bad as 12 mpg on the highway. Like everyone else has said, it all has to do with your driving habits. I find that when I am not the first one through the intersection like I am at the tree, and when I take my time getting places (5-10mph over) I can usually get pretty good gas mileage on a tank. I drive on average 40 miles roundtrip to work and back through construction all the way, and to school, another 25 miles a day, and I cand average about 18-20mpg. I just need to curb my driving habits from time to time, but like this tank, I have gone 150 miles and down to 1/4 tank already. Just depends on how you drive. Chris __________________ 1987 LX, Best times: 13.47 @ 102.49, 1.80 60ft 6900' DA

07-24-2002, 10:54 PM	#17
Patrick Boetticher Registered Member Join Date: Feb 1999 Location: Camarillo/Thousand Oaks Ca Posts: 223	Thanks so much for the help i didnt think id get this many replys but a huge thanks for your suppot!!! -The injectors are calibrated for the meter (all stock) i know thats holding me back... i have a new EEC, and meter no injectors. though. cant afford them GAS IS KILLING ME... -Im Gonna check the coil too and the ingition module... -New distributor makes the car run so much better!!! smother and all!!! i still get a large stumble (feels like a rev limiter) if i put my foot into it at all. espesially abouve 4000. but if i keep it nice and Real slow its fine. did that before the new one too... -Ok 42 PSI ok ill check that!!! -Check codes left bank O2 reads rich and right bank O2 reads lean. im replacing them tomarrow!!! no more codes... I do get on it dont get me wrong!!! But im talking all Highway. -As for the driving habbits no matter who drives the car it gets bad MPG dad, mom, friends ect... soooo im usually pretty good in my dads car i get good MPG, Around 23-24, its a 2000 GT. the highway driving i do is " Put it in 5th AND GO 80" its like 90-100 miles round trip... no traffic usually. - ECT, BAP, and EVP. these were the only ones i cant figure out... -That A/F gauge dosent do $%!* it is the biggest POS. it makes the car sputter and couph when its hooked up!!! I think its broke though. It is hooked up right cuz it hasent always done that.. but it has never read anything worth while to me... its $49.00 light show!!! __________________ Mustang Sold 2003 Ranger Edge

07-25-2002, 12:36 PM	#18
Patrick Boetticher Registered Member Join Date: Feb 1999 Location: Camarillo/Thousand Oaks Ca Posts: 223	ok did some test out of my shop manual evertyhing checks out good exept the coil....and the 02 sensors but thats getting replacesd... thanks for alll the help... illkeep you updated __________________ Mustang Sold 2003 Ranger Edge

07-25-2002, 10:46 PM	#19
Lethal5Oh Registered Member Join Date: Jun 2002 Location: Portage Posts: 239	If your going to replace your coil check out this site www.performancedistributors.com I just got their kit in the mail and its real nice. Have started the car yet because i have a few things to do. check it out. __________________ '95 GT convert. K&N, C&L mass air meter, Performance distributors sreamin demon coil, dyna mod, live wires, king cobra clutch, flowmaster american thunder exhaust, UPR billet adjustable shift handle, Crane Cams Fireball HI-6 box,underdrive pullies, 255lph fuel pump, UPr short throw shifter, caster camber plates, 03 cobra lower A arms, bullit suspension, cobra front brakes

07-26-2002, 10:17 PM	#20
nickj8685 Registered Member Join Date: Jul 2002 Location: Russellville MO, where men are men and sheep are scared Posts: 66	If I could get 20mpg out of my car I would be happy. I usually get 14-16mpg. And it is pretty much stock. But then again I'm running a carb and not efi.