C6 LS2 fuel economy problem!!!
Thread Starter
2nd Gear
Joined: May 2012
Posts: 2
Likes: 0
C6 LS2 fuel economy problem!!!
Hi guys,
I have just bought a 2005 Corvette with 18000 miles on it. This is my first corvette and my first American car. It's also my first post
It was my childhood dream and now it's a dream come true BUT I have a problem. When I drive mildly, I can only get 11 mpg average which I assume is very very low. Everyone here says it's normal for a 6.0L car but when I read other people's averages, mine seems very low.
Now, as for my car's specs;
2005 LS2 A4
West Coast Customs Z06 body kit
Z06 wheels with Nitto Invo Tires(325/275)
Z06 brakes
WCC Head&Cam package(mild)
Vararam Intake
Fast Intake Manifold
3.90 gears
LG long tube headers without cats
H pipe
Corsa sport exhaust
...
I'm gonna DD this car so I don't care how fast it goes. I'm not gonna track it and it's gonna be my cruising car. When I talked to the technician here, he said that if we take out the WCC head&cam package and replace it with OEM and tune it afterwards , I will get %20-25 better mpg. Do I need to take out the whole package or will it be enough if I just replace the cam? Is there any other thing that might cause this irrational fuel consumption in my setup? I have driven a lot of different sports car before so I know it's not my driving. Any help will be appreciated. Thanks guys...
I have just bought a 2005 Corvette with 18000 miles on it. This is my first corvette and my first American car. It's also my first post
It was my childhood dream and now it's a dream come true BUT I have a problem. When I drive mildly, I can only get 11 mpg average which I assume is very very low. Everyone here says it's normal for a 6.0L car but when I read other people's averages, mine seems very low. Now, as for my car's specs;
2005 LS2 A4
West Coast Customs Z06 body kit
Z06 wheels with Nitto Invo Tires(325/275)
Z06 brakes
WCC Head&Cam package(mild)
Vararam Intake
Fast Intake Manifold
3.90 gears
LG long tube headers without cats
H pipe
Corsa sport exhaust
...
I'm gonna DD this car so I don't care how fast it goes. I'm not gonna track it and it's gonna be my cruising car. When I talked to the technician here, he said that if we take out the WCC head&cam package and replace it with OEM and tune it afterwards , I will get %20-25 better mpg. Do I need to take out the whole package or will it be enough if I just replace the cam? Is there any other thing that might cause this irrational fuel consumption in my setup? I have driven a lot of different sports car before so I know it's not my driving. Any help will be appreciated. Thanks guys...
Track Junky
Joined: Jun 2007
Posts: 4,075
Likes: 36
From: Orlando Area
Tech Contributor
Are the injectors stock? If not, the DIC will probably not be perfectly accurate. Also, with those mods I wouldn't expect high mpg around town. My old H/C/I LS2 made about 14 mpg around town and 26-28 on the highway if I babied the throttle.
Drive a full gas tank or two and calculate manually to see if the DIC number is accurate.
Congrats on your first Corvette and welcome to the family!
Drive a full gas tank or two and calculate manually to see if the DIC number is accurate.
Congrats on your first Corvette and welcome to the family!
Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,404
From: Bethesda MD
11 mpg seems low even for a modded car. Are you sure everything is in good running order (e.g. plugs, wires). Who did the tune? A crappy tune with the mods you have could leave up to 3 mpg on the table.
Looking at your list:
Good ported heads should not hurt mpg much. WCC could tell you if they hogged out the ports or just did a light clean-up. If they milled them, the compression bump actually helps with mpg.
Does your car have a high stall converter? That will cost you 1 - 3 mpg in town. Most heavily modded A4s have them, but I didn't see it on your list.
Any chance you find out the cam specs? A mild cam should only be 1 - 2 mpg hit.
Z06 wheels and Invo tires are costing you 1 - 2 mpg compared with stock rims and runflats.
3.90s are costing you 1 - 2 mpg on the highway.
Unless you got a steal, buying a heavily modded car to be your DD when you don't care how fast it goes was not a good strategy. A stock 2006 with the A6 (and maybe an aftermarket tune) would be a better way to go. Before you dump a ton of money into demodding the car, think about whether selling and starting over makes more sense.
Looking at your list:
Good ported heads should not hurt mpg much. WCC could tell you if they hogged out the ports or just did a light clean-up. If they milled them, the compression bump actually helps with mpg.
Does your car have a high stall converter? That will cost you 1 - 3 mpg in town. Most heavily modded A4s have them, but I didn't see it on your list.
Any chance you find out the cam specs? A mild cam should only be 1 - 2 mpg hit.
Z06 wheels and Invo tires are costing you 1 - 2 mpg compared with stock rims and runflats.
3.90s are costing you 1 - 2 mpg on the highway.
Unless you got a steal, buying a heavily modded car to be your DD when you don't care how fast it goes was not a good strategy. A stock 2006 with the A6 (and maybe an aftermarket tune) would be a better way to go. Before you dump a ton of money into demodding the car, think about whether selling and starting over makes more sense.
Last edited by Ragtop 99; May 25, 2012 at 05:34 PM.
Thread Starter
2nd Gear
Joined: May 2012
Posts: 2
Likes: 0
Thank you, guys!
As for your questions; the injectors are stock and no, I don't have a stall converter. And I know it's not very logical to buy a heavily moded c6 for cruising but I live in Turkey and you have very limited options here if you want to buy a second hand vette. A new C6 costs smt like 200k $ here and a Z06 is 275k...Therefore the second hand is very rare as well. I have found one with a good price and low mileage so I went for it
I talked to my mechanic today and I'm replacing the head/cam package with the OEM parts. He also told me that the cam was not mild at all but more like middle/rough and so the car was running very rich until now. So, first we're gonna replace the parts and then they're gonna tune it according to that. I'm gonna post the results afterwards. Thanks again...
As for your questions; the injectors are stock and no, I don't have a stall converter. And I know it's not very logical to buy a heavily moded c6 for cruising but I live in Turkey and you have very limited options here if you want to buy a second hand vette. A new C6 costs smt like 200k $ here and a Z06 is 275k...Therefore the second hand is very rare as well. I have found one with a good price and low mileage so I went for it
I talked to my mechanic today and I'm replacing the head/cam package with the OEM parts. He also told me that the cam was not mild at all but more like middle/rough and so the car was running very rich until now. So, first we're gonna replace the parts and then they're gonna tune it according to that. I'm gonna post the results afterwards. Thanks again...
Burning Brakes
Joined: Jul 2004
Posts: 1,143
Likes: 74
I have no clue what the problem is-- but most cars like yours stock should get in the mid 20's around town & low 30's on the hwy IF DRIVEN NORMAL. Start getting your foot in it and it drops off drastically. But yours is modded but should get way better than what you are getting
