when i first purchased this car i asked everyone here what kind of fuel i should be getting. the response was to stick with the cheap unleaded (87 i think). however i get really bad gas mileage (usually around 200-230 miles a tank) driving mostly highway miles. im wondering if maybe the mods that were on the car mean i should be using a different type of fuel?

only mods (installed professionally by previous owner) are a K&N CAI, short throw shifter, racing springs and exhaust. i like to have fun with the car but no so much so that i should be getting terrible gas mileage.

i havent noticed the car having any problems with the 87 (maybe its 89?). sometimes it gets really loud around 2k rpms but it kinda quiets down after it goes lower/higher. i guess thats the cai maybe?

anyway, just wondering what your opinions are. should i try out some higher grade fuel or am i ok with cheap unleaded?

thanks

 

I would just try empting the tanks of the different octanes and see what one works out the best, and then go with that.

 

Try 89.

By the way, didn't you get manual with your car? It should say in manual what kind of gas your Mustang needs.

 

Every mustang except SVT Mustangs should be running on 87 octane, unless you have a mod which asks for otherwise. I'm not a mechanic or anything, haha; but i dont think any of your mods call for it. When I sold fords the mechanic there told me that, if you put 89 or 93 in a stock mustang (except the SVT ones) the fuel burns uneven because of the additives.. I run 93 in mine but, I have a XCAL2 with the 93 tune.

 

Maybe that's why I can only get 10 mph (I use 89 since day one). However, during the summer I did use 87 once and I didn't notice any gas mileage changes; what I did notice that my muffler was really black (it was less black then I was using 89).

 

yeah, i have the owners manual in my car...it says to use the lowest unleaded stuff (thats 87 i think) which is what i have used. i just wasnt sure if maybe the mods i have call for a higher grade.


<!--QuoteBegin-xxkazp3rxx@November 28, 2005, 10:59 PM
Every mustang except SVT Mustangs should be running on 87 octane, unless you have a mod which asks for otherwise. I'm not a mechanic or anything, haha; but i dont think any of your mods call for it. When I sold fords the mechanic there told me that, if you put 89 or 93 in a stock mustang (except the SVT ones) the fuel burns uneven because of the additives.. I run 93 in mine but, I have a XCAL2 with the 93 tune.

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ok...im still a little confused on exactly what number ive been using...i just know its the cheapest stuff. so basically, youre saying that with my mods i should still be using the cheap stuff right?

that is...unless maybe the previous owner got it tuned for 93 and never mentioned it to me?

 

My 04 will detonate under hard acceleration with anything less than 89, and even sometimes with 89. Your fuel system and injectors may need cleaning.

 

i use 93 on my 92 buts its modified and pings horribly w. anything else. my 04 i use 87 and never have any problems and get 20-25 mpg depending on how many HWY miles i drive i even get 19 on my 92

 

87 = the regular unleaded. You can always eliminate all doubt and tune your car ...

 

I have a guess on what could be causing it.

If you pull your CAI off and check out in front of the MAF, look and see if they left the screen on it. The screen i have seen on some cars when removed will cause eratic idle, bad mpg and even power loss, but on some cars it doesnt make a difference. If its not there, I would put it on there.

The reason it is there in the first place is to smooth out the airflow going across the MAF sensor. it smooths out any turbulence created through the air filter etc.

 

StangFan,

We have the same car and I have never gotten such bad gas mileage. Last tank I got 300 in mixed city driving on 87 octane.
Ho many miles do you have? Your mods are minimal, so I don't think that would affect it.

-Jason

 

yeah, i dont think its those mods unless there are more mods that i dont know about and the previous owner didnt mention.

the car just turned over 63,000 miles. when i got it in june it was around 61,000. ive been keeping the miles pretty low since i dont have it here at school with me...

i think next time im home i will fill up the tank all the way and let it go all the way down to almost empty and see exactly what the mileage is. ill also double check the exact octane ive been using...

 

Just for humor sake, check to see if the maf screen is there. Im really curious on this one.

 

alright..im not really tech savvy though. exactly how would i go about that and is there a chance i could mess something up?

 

Nah you cant really mess anything up. If you look at your air filter, directly behind it will be a plastic round piece that has a square box on it with 3 wires going into it. What we need to see is the front of that round piece so basically remove the air filter. Once the air filter is off, you should be able to look at the front of the MAF housing and it should have a wire mesh screen covering the whole entry area.

 

of course you dont have too, but i got a CAI and exhuast and with 93 octane she runs beautifly so whatever premium is where you live (if you have the money) you could run.

 

watch out on running that premium unless your car is tuned for it... It can burn uneven from what the Ford Mechanics told me... PJ, you said you were right outside of Tampa, where outside of Tampa aare ya?

 

largo, about 3 miles from clearwater beach.

 

ahh ok, I had some friends out there.. was just wonderin, haha.