Worst gas mileage possible with a stock motor

[7upstang91]

Ive never gotten above 180 for a tank ever. Consider yourself lucky to be getting that.

Same here! I get to 160 then the fuel pump whines and loss of all full throttle power. But I still have 3-4 gallons in the tank when I fill up which I dont understand. Maybe when I replace it, it will quit whining and i'll improve my miles per tank.

 

[7upstang91]

Thinking of that, my temp guage never goes up above the second line from the bottom at most?

Mine does that two when I'm driving. But I've heard that these can way off. But mine does go up, only cause I now have a leak.

 

[1987stangman]

I always use premium shell gas and its always 25 bucks to fill up so like 12 gallons each time

With your mods, why use premium gas? That could be your problem. Anytime I used ever mid grade my performance suffered but in your case there if obviously a underlying issue somewhere...My 87' was pretty bad on gas (13 MPG) before the rebuild, now I get around 18. It was a DD car.

 

[old_blue]

287 tonite with 21 mpg. pretty stock though.

 

[f8tlfiveo]

i have 3.55 gears and a stock motor mostly city driving and get about 18mpg in the summer and about 15.5mpg in the winter, i think they put stuff in the gas to help keep it from freezing. every year its the same way, drops in the winter and comes back up in the summer. right now i am still getting 15-16mpg

 

[87MustangGT5.0]

With your mods, why use premium gas? That could be your problem. Anytime I used ever mid grade my performance suffered but in your case there if obviously a underlying issue somewhere...My 87' was pretty bad on gas (13 MPG) before the rebuild, now I get around 18. It was a DD car.

I thought it would be pinging from the timing without it?

 

[NotoriousGT350]

My car has about 214K miles with the motor stock with the exception of a K&N replacement filter. It has an off-road h-pipe, flowmasters dumped, and 3.73s with timing still at 10* using 87 octane.

Best Hwy 24 mpg
City, I usually average about 16 mpg. I have gotten 18 mpg twice in the 6 years I have owned the car.

 

[88mustang92]

i got one for u, i will fill up all the way, drive for a little while until i get to about 1/4 tank left and will fill up. I get 11 mpg, with some beating.....ouch, no egr, no cats...