anyone try 3.08 gears in a Cobra or Mach? looking for mpg

[TerminatedGT]

Looking for mods to help with mileage. I have 3.55 gears now, BBK throttle body, flowmaster cat back and Maf forward cold air I stole from my old GT.
I know keep my foot out of it but looking for high 20 mpg and right now sitting at 21 average. Any info on fuel saving mods would be really nice about now any help is help.

 

[Double"O"]

Lol...you bought the wrong car man. The diff between 3.55 and 3.08 wont be much at all.

I have 3.73 and a blower and still get close to 20 on the highway

When my car was mostly stock i saw 23ish with the 3.27s

 

[PC03GT]

Drive like a bitch, you'll get more mileage. Lmao

 

[baller1svtcobra]

32 valve V8 and looking for good gas mileage? ha! not happening man

 

[VirtualSVT]

With these motors you don't want to lug them at highway speeds for efficiency. I still got great mpg with my 4.56's at 3000 rpm.

 

[xblitzkriegx]

i get 27mpg at 70mph w/cruise on a stock 97 with b heads.

combined, i get about 22, but i run it out every once in a while too. i dont abuse it, but i dont baby it either. refine your driving habits.

 

[snakeraper11b]

Looking for mods to help with mileage. I have 3.55 gears now, BBK throttle body, flowmaster cat back and Maf forward cold air I stole from my old GT.
I know keep my foot out of it but looking for high 20 mpg and right now sitting at 21 average. Any info on fuel saving mods would be really nice about now any help is help.

Buys sports car, inquires in a performance forum on how to convert it to a prius...makes sense :rockon:

 

[01yellercobra]

21mpg is pretty good for these cars. I bet going to 3.08's would kill your mpg. Like Virtual said, these engines hate being lugged. I went from 3.27's to 3.90's and my freeway mileage stayed the same. My around town mileage went up.

 

[DuffManRHA]

You can double your MPG very easy with these cars - sell it and buy a Civic

 

[Charlington]

Only drive downhill.
Sorry, couldn't resist But I wholeheartedly agree with Don't Lug the Engine!
With a V8 or V6 it doesn't sound like you are lugging the engine at low rpm but the rod and crank bearings are getting hammered. To what degree I cannot tell you but if you hate Harleys as much as I then just smile and know they are destroying their engine when they put around at low RPM to make themself sound "bad". 2500rpm is a minimum safe cruise.

 

[BTSMUSTANG]

Like everyone else said, if you want gas mileage sell the cobra and buy a prius, my 99 cobra had 2.73 gears in it when I bought it, 1st gear ran all the way out to 65mph, just plain stupid, swapped in 4.10s soon after.


Ive been able to get 23mpg with 4.10s in my cobra.

 

[Maustang]

Ecoboost swap :shrug:

 

[DSG2003Mach1]

there are calculators online that will show you the change in rpm but the cost of gears + install and something to correct the speedo would buy a lot of gas

something sounds off as it is though, My mach both stock and boltons was around 24mpg if I remember right... I usually cruise at ~8 over the limit

 

[black4vcobra]

Only drive downhill.
Sorry, couldn't resist But I wholeheartedly agree with Don't Lug the Engine!
With a V8 or V6 it doesn't sound like you are lugging the engine at low rpm but the rod and crank bearings are getting hammered. To what degree I cannot tell you but if you hate Harleys as much as I then just smile and know they are destroying their engine when they put around at low RPM to make themself sound "bad". 2500rpm is a minimum safe cruise.

Got anything to backup that 2500 rpm claim? I'm not sure I buy it since I recall being just over 2000 rpm at 70 with the stock 3.27 gears and in 5th.

 

[DSG2003Mach1]

2500 minimum safe cruise? hope youre talking about the Harley since my Mach stock in the 70-80mph range wasnt hitting any 2500

 

[Charlington]

I guess Safe was the wrong word. My 5.0L auto truck has 3.08s and I never use OD so effectively making it a 3sp. When it had 3.73s I got to use OD all the time. My Mustang had 2.87s and I had to keep my foot on the brake when stopped or it would take off and idle down the road or parking lot etc. Also made traffic jams a hassle because it idled too fast (mph).

 

[DSG2003Mach1]

I fail to see what the gearing had to do with it trying to idle down the road, especially a 2.87.... that has to do with some other issue causing a high idle

 

[TerminatedGT]

Drive like a bitch, you'll get more mileage. Lmao

I tried this and got 26mpg 1 time not sure if it was a fluke. Problem is I did that once and it will never happen again lol.

I know there are a couple people here getting good MPG out of these what is your mod list

 

[Charlington]

I fail to see what the gearing had to do with it trying to idle down the road, especially a 2.87.... that has to do with some other issue causing a high idle

Idle MPH not Idle RPM.
750rpm Idle with 2.87 gears = PIA even in 1st gear. Too fast MPH in close quarters like parking lots, traffic jams red lights.

 

[fangs99]

I got 27mpg with my turbo car with 3.73's and a viper spec t-56 at around 90mph. car loves to cruise around 2,200 rpm minimum. but I honestly care less about economy.