big cam=kill gas mileage?
big cam=kill gas mileage? hey guys,i want to install a heads and cam package on my 99 ws6 that will get me to about 425 hp range at the wheels, but my car is still a daily driver and would like to know how bad my fuel economy will be. its a manual 6 speed with full exhaust and intake bolt ons with a moser 9in rear and a 389 gear. any idea?
those gears really shouldnt effect his gas mileage. I put 4.10s in my rear when the stock 3.42 broke and I saw no decrease in gas mileage maybe just like 1 mpg on the highway
if worried about mileage, get a mild cam, something like a 228, and keep the valve overlap to a minimum. the 228 is a great cam that LOTS and LOTS of people run and it still will get you very close to your hp goals.
I agree with the statement above...ive had cams with varying sizes of lift and overlap. Ones with mild lift and less overlap seemed to get much better gas mileage. I had a huge cam once with a ton of lift and huge over lap and i swear when the cam would thump at idel, I could watch and smell gas escaping out of the tailpipes! hahaah
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TECH Enthusiast
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From: Denver International Airport, Colorado USA
I am H/C with a 3.90 rear gear.
Our speed limit on major Highways is 75 mph. Of course I cruise at 80 mph..turning about 2050 RPM. I get 26.5 mpg at that speed.
I think it is a myth that a car with a performance cam kills gas mileage. In a lot of cases your are actually improving the efficiency of how well your car performs.
What will kill your gas mileage is your right foot. It is virtually impossible to drive a H/C without occasionally hitting a on ramp at >50% throttle. The more you do that, the more you see your gas mileage drop.
With gears it is probably what speed and RPM you drive at. It might drop your gas mileage somewhat in city traffic. But, in my case highway cruising saw no drop. In fact I get about an additional 20-30 miles a tank since going H/C.
I would not worry about it. Anybody else have similar experiences, or I am the exception?
Our speed limit on major Highways is 75 mph. Of course I cruise at 80 mph..turning about 2050 RPM. I get 26.5 mpg at that speed.
I think it is a myth that a car with a performance cam kills gas mileage. In a lot of cases your are actually improving the efficiency of how well your car performs.
What will kill your gas mileage is your right foot. It is virtually impossible to drive a H/C without occasionally hitting a on ramp at >50% throttle. The more you do that, the more you see your gas mileage drop.
With gears it is probably what speed and RPM you drive at. It might drop your gas mileage somewhat in city traffic. But, in my case highway cruising saw no drop. In fact I get about an additional 20-30 miles a tank since going H/C.
I would not worry about it. Anybody else have similar experiences, or I am the exception?
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I have a 421" motor with a 239°/247° 110°+2° breathing through a single plane with a 4 BBL throttle body. My city mpg sucks---about 12 mpg. But cruising the interstate at 75-80 mph gets back to 23 mpg. I also have the six speed and 3.89 gears.
From Exp. Gas Milage can def be effected by things like the tune of the car, weight, gearing, and driving style. Cam Reversion makes up another part of the situation and as the cam gets bigger, the reversion increases and milage decreases.
If your a Z06, I expect with a mild cam, tune, and the proper rear gear that you may get 25-29 mpg if not more, but on a heavier FBody. and Less trans gearing, even be it a m6 trans. These car often run lower MPG #'s
If your a Z06, I expect with a mild cam, tune, and the proper rear gear that you may get 25-29 mpg if not more, but on a heavier FBody. and Less trans gearing, even be it a m6 trans. These car often run lower MPG #'s
It all depends on how you drive, and how well the car is tuned after the cam is installed. I am not in the F-body scene, but I know several guys running 5.3's and 6.0's with H/C and LS6 intakes, one is a turbo, and gets 29mpg. It's all in the tune, and how you drive. BTW, the one that gets 29mpg runs in the 9's and is a member on here. His name is Black-X. He is a tuner.
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Joined: Jan 2010
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From: Euless Tx
thanks for all yous input guys. i want to make more power but am still trying to be practical. my options are heads and cam for about $2500 or a used procharger set up for about $4000.
If your goal is 425 rwhp, you can attain that with these heads: http://www.texas-speed.com/shop/item...id=84&catid=40
And a mild cam such as a 224ish duration cam.
And a mild cam such as a 224ish duration cam.
I am H/C with a 3.90 rear gear.
Our speed limit on major Highways is 75 mph. Of course I cruise at 80 mph..turning about 2050 RPM. I get 26.5 mpg at that speed.
I think it is a myth that a car with a performance cam kills gas mileage. In a lot of cases your are actually improving the efficiency of how well your car performs.
What will kill your gas mileage is your right foot. It is virtually impossible to drive a H/C without occasionally hitting a on ramp at >50% throttle. The more you do that, the more you see your gas mileage drop.
With gears it is probably what speed and RPM you drive at. It might drop your gas mileage somewhat in city traffic. But, in my case highway cruising saw no drop. In fact I get about an additional 20-30 miles a tank since going H/C.
I would not worry about it. Anybody else have similar experiences, or I am the exception?
Our speed limit on major Highways is 75 mph. Of course I cruise at 80 mph..turning about 2050 RPM. I get 26.5 mpg at that speed.
I think it is a myth that a car with a performance cam kills gas mileage. In a lot of cases your are actually improving the efficiency of how well your car performs.
What will kill your gas mileage is your right foot. It is virtually impossible to drive a H/C without occasionally hitting a on ramp at >50% throttle. The more you do that, the more you see your gas mileage drop.
With gears it is probably what speed and RPM you drive at. It might drop your gas mileage somewhat in city traffic. But, in my case highway cruising saw no drop. In fact I get about an additional 20-30 miles a tank since going H/C.
I would not worry about it. Anybody else have similar experiences, or I am the exception?
