Mine is on the smallish side and about 2 mpg is what I lost. 
Heads/cam mpg?
Drifting
Joined: Mar 2005
Posts: 1,424
Likes: 21
From: Placitas New Mexico
Boy, this is a timely question! Most guys will respond that they don't care and you shouldn't either or you shouldn't have bought a Corvette. For me the great fuel mileage on the C6 was a selling feature. I have bolt ons and a cam could be next, but I am concerned about fuel mileage also. When you buy a Corvette you know your going to have your foot in it and I'm willing to pay for that priviledge, but a cross country trip is where you'd like to keep that 30 MPG! Flame suit on!
Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,402
From: Bethesda MD
Race Director
Joined: Nov 2005
Posts: 14,548
Likes: 1,539
From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
Katech Street Attack forged engine (582/555 SAE) with their Torquer cam here and I get 25-27mpg on the freeway at 70mph, about 2 mpg less then stock. my other previous can got about 20-22 mpg because of more everlap.
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Burning Brakes
Joined: Jun 2008
Posts: 1,214
Likes: 3
From: CA
It depends on the combo you go with. You won't notice much drop on the FWY. Most of the MPG drop is on the street. On the FWY I still get about 28-30MPG. On the street, that's a different story, especially if you're always in traffic.
Le Mans Master
Joined: Dec 2005
Posts: 6,998
Likes: 1,681
From: Southeast TX
The highway mileage was 2-3 mpg less with 232/234 cam, bolt ons, and stock LS3 heads. The city was where the MPG really went south. I don't do a lot of city driving, but did notice a huge difference after the cam swap. I'd estimate 5 to 7 mpg less than pre cam. Tolerable on the highway, horrible in town.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
mods
guys it also depends on all mods, even tires, asking heads and cam mileage can really vary depending on the cam and the gears you need, with my mods 19-21 mpg at 60 mph 2000 -2100 rpm
Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,402
From: Bethesda MD
gears -1
wheels and tires -1
cam -2
Highway mpg about the same loss maybe a little less. I recently saw a little above 26 on the highway at 70 mph, not dragging the A/C.
Racer
Joined: Apr 2005
Posts: 351
Likes: 0
From: Louisville Kentucky
My car is a 2005 manual with an LS2, so it isn't really what you asked about but my freeway mileage increased when I got the cam. I don't know about in town. I drove from Decatur, IN to Louisville, KY on a warm May day with air on. Most of the way I was in 6th at 77 MPH. the DIC indicated 35/36 on flat spots. Most of this drive was one big flat spot. When I checked the actual mileage, it was "only" 33, so the DIC was a little generous. My car has a Crane Cam with 228/232 duration, 600/600 lift, 112 LSA and 5 degrees of mechanical advance. It also has a Honker, a FAST, TFS 225 heads, Dynatech headers, a UD pulley and a small thing or two that I have forgotten.
Pre-cam/heads the DIC indicated 30/31 on flat spots and with no mods it indicated 27/28.
Pre-cam/heads the DIC indicated 30/31 on flat spots and with no mods it indicated 27/28.
Former Vendor
Joined: Aug 2005
Posts: 16,897
Likes: 412
From: Lewisville TX
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
Depends on the combo,
In the past when we have done both head and cam packages I will generally raise static compression to some degree, based on fuel used.
That being said, they generally drop around town a few mpg, and highway remains relatively the same given no other changes. I have seen as high as 28 mpg on a 500 rwhp LS2 combo on strictly highway runs.
In the past when we have done both head and cam packages I will generally raise static compression to some degree, based on fuel used.
That being said, they generally drop around town a few mpg, and highway remains relatively the same given no other changes. I have seen as high as 28 mpg on a 500 rwhp LS2 combo on strictly highway runs.
Advanced
Joined: Feb 2011
Posts: 93
Likes: 0
From: Charleston SC
I have TSP 231/236 LS3 Cam with the rest of the supporting mods.. Around town seems to have dipped but highway remains at 28+.. Granted my power band moved up.. Need to do 80-85 to get the best MPG.
