Why do Cobras get low MPG?
- Thread starter rdefino
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01SilverL
Founding Member
24? The best I have ever seen was 16, and with the kenne bell it's now under 10mpg. Back to the orginal question, Cobra's make more hp and weigh more than both the vette and gto.
the Cobra has a supercharger which means it's producing drag on the engine while cruising and not getting much benefit from the supercharger. the Vette is light and aerodynamic. and with the abundent low end torque of the n/a LS1/2/6 engines, it can cruise at lower rpms.
BZ's_03_SVT
New Member
if ya want the boost gauge to go up, the fuel guage must go down! i can blow a 1/4 tank in a 10 mile stretch of city driving. Best MPG on a 13.5 gallon tank has been 225 miles
EvilEyez
New Member
QUICK91LX
Founding Member
GM seems to have perfected their tranny/rear gear combos to optimize performance and fuel economy. they have been doing it since they came out with a 6-speed. but yeah the blower on the cobra makes gas mileage take a crap
Emil
New Member
For the S/C'ed Cobras the compression ratio has been lowered to 8.5:1 for detonation control at high boost, unfortunately for normal cruising it hurts efficiency. I do manage to get right around 20mpg going to work with a mix of hwy and city driving. Not bad for the performance level of the car 
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BLK_ROUSH
Founding Member
Emil said:For the S/C'ed Cobras the compression ratio has been lowered to 8.5:1 for detonation control at high boost, unfortunately for normal cruising it hurts efficiency. I do manage to get right around 20mpg going to work with a mix of hwy and city driving. Not bad for the performance level of the car
I agree, same here. I wouldn't lay it all on the S/C. My roots blown 98GT gets 20-23mpg so it's comparable despite the power difference.
The vette's 6th gear is a huge overdrive. I've driven oen and at 100mph it is barely over 2000 rpm.
It's also lighter than the Cobra.
The aerodynamics are probably better.
I did notice on the 03 cobra that you get pretty good mileage going in 6th doing 90mph or so. Drove it for quite a while and defintely got 20+mpg (probably close to 22)
Normal daily driving, trying to keep the rpm's low doesn't seem to matter much in it's thirst.
It's also lighter than the Cobra.
The aerodynamics are probably better.
I did notice on the 03 cobra that you get pretty good mileage going in 6th doing 90mph or so. Drove it for quite a while and defintely got 20+mpg (probably close to 22)
Normal daily driving, trying to keep the rpm's low doesn't seem to matter much in it's thirst.
I've gotten 26mpg with almost all freeway driving and my last mod gave me ~ +1 mpg (didn't expect that). But the #1 reason the vette gets better mpg is it's aerodynamics. Compare the drag on the vette vs. the mustang chassis(just look at the bland styling of ALL econo-boxes, bland jellybean = aerodynamic). The faster you go the more it becomes obvious that the vette is much more efficient. Pushing a wall of air at 60+mph is not easy, but moving to the side as you pass by is. I'd say that is the same reason the gto gets better mpg(the ls1 jelly bean). Now why is the mustang so bad in this area? Old platform + 4v heads for the cobra on a mod motor and it gets tall in a hurry, add the requirement of some style and voila, mpg sacrifice.
Also consider that the modular motor idea isn't quite as dialed in as the chevy's (it's newer). The next two things that effect the mpg of these cars is the efficiency of the drive train, more $$ on a tranny gets you more efficiency(via gear materials, bearings etc.).
Weight has little effect on the freeway(assuming constant speed), other than making the wheel bearing friction losses greater (not much). Weight does effect mpg while accelerating though.
Also consider that the modular motor idea isn't quite as dialed in as the chevy's (it's newer). The next two things that effect the mpg of these cars is the efficiency of the drive train, more $$ on a tranny gets you more efficiency(via gear materials, bearings etc.).
Weight has little effect on the freeway(assuming constant speed), other than making the wheel bearing friction losses greater (not much). Weight does effect mpg while accelerating though.
WHO GIVES A **** its a god damn chebby piece of **** if u actually think about buying a goddamn piece of **** new GTO over a goddamn sweet ass 03 04 cobra just because it gets a little better gas mileage then u don't deserce to operate one of theasde machines u don't drive a cobra if u are worried about ga milage u drive a goddamn pice of **** civic or camary not a ****ing cobra ITS a goddamn beast and beasts don't get good gas milage
