Mpg questions.

[94RedGt]

I always wondered if my car is actually doing the correct mpg, it runs fine and it does not have alot of mods, just a cobra intake and full exhaust. I filled up the tank yesterday and decided to drive it for a while and managed to consume half a tank of gas driving around on highways at around 55 to 70mph with some city driving mixed in. I only managed 105 miles until the needle reached half a tank on the gauge. Does this sound ok or should it be able to get more miles.

The car is a 94 5.0 with a 5speed and stock 3.08 gears.

 

[ttocs]

13 gallon tank means that 105 miles/6.5 gallons = a little over 16 miles/gallon. My stock 94 gt with nothing on it driving from az-in was just over 25 mpg. Doesn't sound right.

 

[silverv6]

Seems low if you were driving on the highway as much as you said..

 

[joekd]

Depends on how "gentle" you were with the throttle, all it takes is a couple WOT blasts to throw your MPG in the toilet

 

[CC'S95GT]

I'm getting about 18-19 mpg with my stock, 200,000 mile motor. I do have headers and full 2 1/2" exhaust and a CAI.BUT I also have 4:10 gears.90% of my driving is interstate at 75 MPH

 

[gopher_6_9]

You can't go by the gauge... The stock clusters are notoursily shitty and inacurate.

You must go by milage and actual fuel consumed. You need to fill up the tank, run it till empty, fill it up again. Take the amount of gallons input and divide the miles traveled. That will take out the guess work that you are trying to do and give you MPG.

That is assuming you have stock gears, stock tires, and your speedo is accurate.

 

[LilRoush]

^^ This.

 

[crrobinson13]

13 gallon tank means that 105 miles/6.5 gallons = a little over 16 miles/gallon. My stock 94 gt with nothing on it driving from az-in was just over 25 mpg. Doesn't sound right.

It is a 15.4 gallon tank

 

[5.0kid]

ha, i'd love to get 16mpg highway! last time on a 200 mile trip I had to fill up! got 11.8mpg cause of the wind coming 60mph at me! but even my carbed 347 will get over 100 miles for half a tank...without wind lol

 

[lutter94]

You can't go by the gauge... The stock clusters are notoursily shitty and inacurate.

You must go by milage and actual fuel consumed. You need to fill up the tank, run it till empty, fill it up again. Take the amount of gallons input and divide the miles traveled. That will take out the guess work that you are trying to do and give you MPG.

That is assuming you have stock gears, stock tires, and your speedo is accurate.

You shouldn't have to run it empty, just fill up, reset the trip, then fill again later and do the math.....

 

[Slykin]

Find the REAL mileage and come back with that. Doing it by "half tank" is useless. A half tank on your gauge could be just about anything.

 

[justinschmidt1]

It is a 15.4 gallon tank

Well on the gauge from e to f its probably a 13 gallon range...the 2.5 is reserve.

Anyways, that sounds low for you car.....my car with me beating on it, stalld auto, and over 400 rwhp would do that kinda MPG if not better.

 

[94mustanggtfast]

yea i got 20mpg highway the other day

 

[94RedGt]

Well have driven close to 150 miles already and the needle is almost at the last 1/4 .

 

[Twista]

With 95 GT i was getting crazy low mpg's also. I never drove the car down to 0 to test it when i got the car it, but my float inside my tank was slowly discintaging (spelling) over the years where it wasn't even accurate. Till it got real bad where i could fill the car up and the gas gauge would only go to HALF FULL on a FULL Tank of gas. Months after that it would stay @ empty no matter what.

A new fuel sender unit fixed my gauge.

So who knows without doing math if your sender is going bad. If your handy you can drop the tank and check the conidition of your float. If its going bad then your fuel reading could be wrong.

 

[Ferocious]

I usually try to get an average of 175 miles per tank. 90% city driving.
If i'm near that mark, i'm driving well..

 

[94RedGt]

Find the REAL mileage and come back with that. Doing it by "half tank" is useless. A half tank on your gauge could be just about anything.

Im not doing it by half the tank, i know the gauge is probably not accurate but what i was saying is that the needle is already at half a tank and i only drove it for 105 miles. Even if the needle is not dead accurate i bet its probably close to being half of a full tank of gas.

Ok it looks like im only going to manage around 160 to 170 miles per tank, needle is already at one 1/4 and at around 155 miles. I will take my maf sensor out and clean it and also going to see if i can change the coolant temperature sensor since its not that expensive and i have been told thats one of the sensors you replace along with other stuff when doing a tuneup.

Also another thing, does having no EGR make any difference in MPG ? Mine is still hooked up to the ECM and has vacuum but its not connected to the headers because i dont have the tube that makes the connection , and even if i did i would need a longer one cuz i got an inch spacer on my car due to the valve covers hitting the cobra intake because they are Fox valve covers.

 

[RockstarMentality]

I get 18-19 mpg at about 70% highway coasting around 2.6-2.9k rpms. I realize I have 3.73s, but this seems low to me. Shouldn't intake/exhaust give me a couple of those MPGs back? Or is an engine with 140k really going to get that bad gas mileage?

 

[blackpony]

My 450 hp 347 would average 17 ish on a mix drive hwy and in town..

 

[gopher_6_9]

You shouldn't have to run it empty, just fill up, reset the trip, then fill again later and do the math.....

Yeah you don't have to run it to empty, but what you want to do is put the most miles on a tank, this gives you a better average than putting 30 or 40 miles on it and then filling up and figuring mpg.