>19 mpg hwy??

[Shirley1978]

I drive my mach quite a bit. About 60hwy 40street. on average im getting about 17mpg, just last night when i took a long drive (20st 80hwy) I only got 18mpg... WTF?

I had an OR h pipe on it and went back to the stock midpipe and magnaflows thinking it was the OR h pipe that was giving me problems (engine lights come on and off etc) but it did nothing. :nonono:

all the 02 sensors are fine, as far as i know the car isnt tuned (or else it probably wouldnt be throwing check engine lights with the OR pipe).

any ideas what it could be?? I dont beat on the car much, just on ramps etc. i set the cruise control at 70 when im on the freeway and still get this crappy mileage.

WHAT GIVES?? im averaging 220 miles per tank!!

-Jonny

 

[watman02]

do you have gears, is it a auto, how do you drive be honest??? have you checked for codes, how about a tune up , air filter, fuel filter start small.

 

[Shirley1978]

No mods besides magnaflo cat back and a k&n filter.
It's a 5 speed. I drive pretty easy 70% of the time, had a 78vette and crashed it a year ago, still haunts me.
No gears. No other mods besides the above. Had a fresh oil change when I took the OR pipe off.
I have 18" fr500s on the car, but it shouldn't be affecting the mileage that much. I'm thinking maybe I gotta change my spark plugs?? No idea really...

 

[Shirley1978]

I checked the codes and it was throwing some random codes, can't remember exactly what it was tho..

 

[4a7191a]

try the plugs, clean the maf sensor with the 3m spray stuff. some people hate seafoam, i like it. it helps. ive gotten 22mpgs and ive got 456's and cams.
as far as plugs go , i perfer the ngk tr55's.

 

[kevin01cobra]

Are you sure you are estimating MPG's correctly? How are you doing so?
On the 80 hwy and 20 st you should be getting much more if you are only going 70. I can do about 190 hwy miles (at 80 avg) and 70 st miles (kind of abusive) and end up at 20 mpg.

 

[Shirley1978]

ill need to check the maf sensor, as far as calculating mpg, i set my trip meter everytime i fill up. everytime my low fuel light comes on i look for a gas station and fill up. take the miles on the trip meter and divide by the number of gallons it takes to fill up. as far as i know thats how you do it.

:smmon:

 

[DarkMach1]

Do a full tune up, air filter, fuel filter, plugs, maf cleaning, etc. Im getting 22mpg(about 220miles and still got a 1/4 tank left).

 

[NastyNate420]

+1 on the tune up and cleaning the maf and a new fuel filter as well.
I get 300+ miles on a tank of gas and i have over 100k miles on her.

 

[2007ShelbyCobra]

your lucky, I guess idk whats wrong with mine, but I sure as hell dont get 18

 

[Krwy]

I avg about 200-220 a tank. Doesn't bother me, its a GREAT 220 miles, seeing as how I only drive it on the weekends, and my daily is a slllllloooooowwww 91 2.3 Ranger. Get a custom tune from Amazon Tuning Solutions, it should help.

 

[gamatt]

I avg about 200-220 a tank. Doesn't bother me, its a GREAT 220 miles, seeing as how I only drive it on the weekends, and my daily is a slllllloooooowwww 91 2.3 Ranger. Get a custom tune from Amazon Tuning Solutions, it should help.

+1 on the tune. I went from 17.x to 19.x mpg 60/40 city/hwy. And the extra 30whp adds some fun too when you want it. :banana: :burnout:

 

[EVO-lution]

before I gutted my car and sold the motor/trans/ and rear I was getting about 270miles per tank.just had O/R X and straight pipes as far as mods.

but I have to agree with most others, do a full tune up. :thumbsup:

 

[Shirley1978]

thanks for the replies guys. I had a feeling I would need a tune, that crappy mpg just wasnt making sense.

any recommendations on what plugs and fuel filter to use?

 

[fire_4_effect]

i don't care too much for the mpg... i just fill-up and roll!

 

[4a7191a]

motorcraft fuel filter, i perfer the ngk tr55's

 

[Shirley1978]

i don't care too much for the mpg... i just fill-up and roll!

Well apparently I'm not as care free as u are btw, I love your car.. Wish I could have found a white terminator

 

[Roots-type]

Winter fuel sucks balls. My mpg has taken a noticeable hit as well.

 

[VirtualSVT]

on the highway keep the rev's around 2800-3000 and you'll get great mileage.

 

[4a7191a]

lol, i ave. around 2650rpms with the 456's lol. straight up city driving is around 11mpg's.