nemethjames1

fast83, you must have a massive carb and cam on your ****.............. i had (just sold) my 65 tbird that got 5-8 mpg, thats about 20 bucks a day for in town driving

kellys95gt

I only get 13 mpg.

roundman

with an AOD and 3.73 gears in my 88, I used to get about 17-18 mpg driving back and forth to work,which was about 10 miles of interstate at 70 mph and then 8 miles of primary highways with about a half dozen stop lights along the way. on the highway cruising at 70 mph, the engine was running about 2,300 rpm and I could pull down over 20 mpg which I feel is damn good for a 5.0L that will outrun lots of other cars out there.
back when it was new, stock with 2.73 rear gears, on a cool day without the AC on I averaged 27 mpg with it going from Richmond to Englishtown, N.J. on I-95 and the Jersey Turnpike where I was cruising at 70 or so with the CC on.
BUT I DIDN'T BUY IT FOR THE GAS MILEAGE, I BOUGHT IT FOR THE GO FAST FUN FACTOR!!!!
Like vfast said, if mileage is your concern, you bought the wrong car, go by a damn ricer and get out of here! LOL

blue89

I'm just trying to get the best performance out of it but also not wanting to run it to rich. I checked my plugs when I chaged the wires. They looked normal. No black deposits or any carbon build up. I'd say the beast is running pretty well. I have yet to install the new coil becaus the old ones bolt are rusted and starting to round off. The bolts are also the tween side too.

diablo9861

dude, im getting only 16 miles a gallon on my convertible 5 speed. Im thinking my problem is in my tranny or gears. SIcne it was origianlly a 4 banger it might have retarded tranny or geras in it. I still havent got that far with my car. Im usually getting 200-220 a tank depending on if im driving any highway at all, and the palce i get my gas. i notice a few places if i buy there gas i get crappy gas mileage. So i stay away from them now. Any clues on what my problem could be and how to check the tranny and rearend/gears? thanks

nemethjames1

if it was a 4 cyl car it has a 7.5 inch rear end, was it stock with auto or manual? you might have some 3.73's in there already..... 7.5 isnt as srong, but as long as your not running slicks, theres no worry.... you can pull your differential cover off, count the teath on the ring gear, and count the teath on the pinion gear, and divid them by eachother, you'll get the current gear ratio

diablo9861

ill find what gears it is, asap, and inform the forum, but would this gear/rearend difference be that big of probelm to my mileage situation? i have been dealing with my head question that is if i have cobra heads, with a regular inatke would this be a leading reason for bad gas mileage/power lag/lacking?

nemethjames1

if you got cobra heads, that would make your mpg go down a little, you cant gain horsepower and gasmileage, its a rare thing for sure... and having that rear end wouldnt neccesarly be a bad thing unless you were drag racing... i too have 3.73s, if you have that even