gas mileage

[ike34]

What is the gas mileage for a stock 1991 5.0L mustang, like city and highway numbers?

 

[TRWXXA]

As the advertisements say, "Your mileage may vary."

This weekend, I averaged 24mpg on a 700 mile round trip. All interstate, and I kept my speed down around 72 mph because I was convoying with someone else. Pretty good considering I have 3.73s.

This is up from the usual 19 to 21 mpg I was getting. A new air filter, some injector cleaner, and some new vaccum lines probably helped as much as keeping my foot out of it.

I imagine you could do just as well with your '91.

 

[BelueLX]

i get around 270 miles on 13.3 gallons to and from work stop and go in my 88 LX. thats 20.3mpg. never ran a full tank of gas out highway driving.

 

[HISSIN50]

15 in town if im lucky.

 

[sidewayzisbest]

umm depends on your driving habits =p

 

[Michael Yount]

sidewayz is right - driving style and traffic are HUGE factors making it difficult to compare. In big metro areas where a driver might spend a lot of time in bumper to bumper traffic during a commute, you might be doing really good to see 13-15 mpg. For more suburban/rural areas where 'around town' means less bumper to bumper and more 30-45 mph cruising, the same car might get 18-20 'around town'. Highway comparisons are pretty valid - as long as the speeds are similar.

Mine has mild mods (about 270HP/330 torque crank numbers) and the equivalent of what would be 3.90 gears in a stang (5 speed, .625 5th). I've consistently gotten 18-19 mpg in town (suburban - very little stop and go), and recently completed a 525 mile round trip running 65-70 on the Interstate - used 20.0 gallons -- 26.3 mpg. Same engine in a Stang I think might get a mile or two better highway numbers due to the Volvo's 'brickish' aerodynamics.

 

[Idwitheld-1`]

15.9 hwy / city combo driving.
12 city

ouch...that sucks.

 

[ALMOSTFINISHED]

Boy, everybody is real lucky there. I do mostly stop and go driving and get about 140 miles out of a tank. my best was 200 out of a tank on a road trip. I only run 93 octane, its been tuned, new 02's and all. The car has done this the 3 1/2 years of ownership. At first i thought something may have been wrong but when my friend bought a 92 gt and he was getting the same out of a tank with stock gearing as opposed to my 3.73's I felt alot better.
Sorry to cut short but i gotta go fill'er up!

Nick

 

[Michael Yount]

Nick - have you tried running lower octane? Unless it's keeping you out of detonation with your timing, it may pick up a mile per gallon or so if you drop back to 89 or 87 octane. There's no benefit to running 93 unless it's keeping you out of detonation -- it's harder to ignite and burns fractionally slower than the 87. Mine's running 16-18 degrees of initial, 32-34 degrees total and with aluminum heads, I'm still running 87 octane without any trace of detonation.

 

[super302]

i squeezed out 19 all city once, i could prob. get 20 if i try...never been on the interstate

 

[sidewayzisbest]

i usually get 18-20 mpg its mainly in your tune ....but also i do have to give it 2nd gear a couple times =p

 

[Michael Yount]

super - we gotta get you outta Iowa on the Interstate!

 

[ALMOSTFINISHED]

Michael- I never thought of that, but to be honest with you i may give it a shot and see if i can pick up any. I assumed with the advanced timing that i would get pre det. I'll try it this week and post a reply.

thanks very much for the info. any help in gas milage would be great. super averages about $2.38 a gallon here.

thanks again

Nick

 

[super302]

super - we gotta get you outta Iowa on the Interstate!

I know

 

[Michael Yount]

Nick - if nothing else, it'll save you per gallon. There's a common myth that the higher octane fuels are somehow 'better' for your car; but unless they're keeping you out of detonation at the timing you want to run, it's just wasted money. There's no other benefit at all.

 

[roush 97]

I get about 24 mpg highway with stock gears. City it can drop to 17 or 18 if I really keep my foot in it. Still better than my 6 banger Ranger that gets about 14 or 15 no matter what..