[Z06] Very Dissapointing Mileage
Safety Car
Joined: Oct 2001
Posts: 3,504
Likes: 25
From: Insert Wittty Comment here
Ummmm no. My car which is stock averges about 28MPG around 70-75. I have not done a long enoug cruise at 80 to see what it averages, but I know its not an 8mpg delta.
Drifting
Joined: Apr 2000
Posts: 1,390
Likes: 36
From: INDIANA
If your car is getting lean codes, then obviously something is wrong. You could have an air leak, bad O2 sensor, or something else, but be sure of one thing: If you have lean codes, the computer is also trying to add fuel, which is going to hurt mileage, especially cruise mileage. Most relatively stock Z06s don't have a problem getting upper 20's at 70-75, steady state cruise.
Drifting
Joined: Jul 2005
Posts: 1,506
Likes: 5
From: Milpitas CA
Obviously there are no absolutes and your mileage may vary.
Dog
Safety Car
Joined: Oct 2001
Posts: 3,504
Likes: 25
From: Insert Wittty Comment here
I beg to differ. If you looked at the test I did, 70 mph equated to approximately 31 mpg, 80 mph equated to approximately 23 mpg. Personal driving habits will have a large impact on individual mileage, but it's pretty clear where the mileage drops off in these cars. In my car, on flat ground, while on cruise control, above 70 mph it drops off significantly.
Obviously there are no absolutes and your mileage may vary.
Dog
Obviously there are no absolutes and your mileage may vary.
Dog
So, I am basing my mileage numbers on steady state highway driving for a full tank of fuel. I have done shoter runs where I can maintain 80 MPH for shorter periods, but I have not been able to maintain 80MPH for an extended period of time such as a full tank.
I will re-check again on my next trip, but I do not believe my experience has been nearly that dramatic in 5MPH.
Tech Contributor
Joined: Oct 1999
Posts: 41,062
Likes: 9,825
From: Charlotte, NC (formerly Endicott, NY)
Actual MPG (fuel economy) in itself really isn't a "concern", but I AM a bit concerned that my apparently well below mpg may be a symptom of something mechanically wrong (hope that made sense).
Tires are stock sized Wide Ovals on stock wheels, so I can take that out of the equation.
I was under the impression that if anything the Vara-Ram would increase mileage, but I can see the argument that if the car thinks it's too lean it could very well be injecting more fuel to compensate.
I'll have to use the scanner to take some readings next time as well.
Tires are stock sized Wide Ovals on stock wheels, so I can take that out of the equation.
I was under the impression that if anything the Vara-Ram would increase mileage, but I can see the argument that if the car thinks it's too lean it could very well be injecting more fuel to compensate.
I'll have to use the scanner to take some readings next time as well.
Bill
Pro
Joined: May 2002
Posts: 552
Likes: 0
From: Meadows Place Texas
Since new, my 2001 Z06 consistently gets 29 to 30 mpg on the highway (running cruise control between 70 and 75 mph). In town, I am all over the map, anywhere from 17 to 21, depending on time stuck in traffic, how heavy my foot is (I use 3K rpm as my normal shift point for 1, 2, and 3), and the mix of interstate and city streets on my drive.
I always use 93 Octane Shell. I believe it makes a difference. I've talked to people using regular, and mid-grade gas. The on-board computer adjusts the tuning for the lower octane. Just going to the mid-grade gas drops 10 to 15 % of the rwhp and, I believe, significantly reduces gas mileage.
Dr. Dave
I always use 93 Octane Shell. I believe it makes a difference. I've talked to people using regular, and mid-grade gas. The on-board computer adjusts the tuning for the lower octane. Just going to the mid-grade gas drops 10 to 15 % of the rwhp and, I believe, significantly reduces gas mileage.
Dr. Dave
Team Owner
Joined: Aug 2006
Posts: 30,897
Likes: 45
From: Picking on the weakest kid in the yard.
Some of your problem is the tires. I have WOs on my Z but I also have a complete set of SC tires on rims that I can put on the car. When I went to the WOs my mileage dropped by 2 mpg. A couple of months ago I put the SCs on to use them at the track and for some cruising. I gained back my 2 mpg. Not sure what the difference is other than the WOs may have more rolling resistance.
Bill
Bill
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
Put the stock airbox on and reload the stock tune. The car might actually be faster in stock form.
Last edited by RussBt; Nov 15, 2008 at 10:25 AM.
Drifting
Joined: Apr 2000
Posts: 1,390
Likes: 36
From: INDIANA
Some of your problem is the tires. I have WOs on my Z but I also have a complete set of SC tires on rims that I can put on the car. When I went to the WOs my mileage dropped by 2 mpg. A couple of months ago I put the SCs on to use them at the track and for some cruising. I gained back my 2 mpg. Not sure what the difference is other than the WOs may have more rolling resistance.
Bill
Bill
Tech Contributor
Joined: Oct 1999
Posts: 41,062
Likes: 9,825
From: Charlotte, NC (formerly Endicott, NY)
If the WO's have a larger diameter (I know the tire size is the same but maybe they are taller anyway, just as WO's seem to have less treadwidth than other 295s), then the car will be traveling faster than the computer thinks it's going and will therefor calculate a poorer MPG than it would with a smaller tire, despite the fact that in reality, you will be getting better MPG than a smaller tire.
Bill
Tech Contributor
Joined: Oct 1999
Posts: 41,062
Likes: 9,825
From: Charlotte, NC (formerly Endicott, NY)
Bill
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Reading this thread makes me think I am not getting the mileage out of my car that I should be able to get. I drive 31 miles each way to work and usually on reach 60 MPH or so. I only have 2 redlights during this trip. My car according to my records, over 20k miles, I have averaged 25.1 MPG. My car is bone stock. Oil changed every 5k miles, new air filter every 15k. I have not checked the plugs to see what they look like.
Any thoughts on this one? Think the mileage should be better? I am usually pretty easy on the car. I may change gears at around 2500 RPM through the first 3 gears. Then just lazily shift into 6th and cruise to work.
Any thoughts on this one? Think the mileage should be better? I am usually pretty easy on the car. I may change gears at around 2500 RPM through the first 3 gears. Then just lazily shift into 6th and cruise to work.
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
Reading this thread makes me think I am not getting the mileage out of my car that I should be able to get. I drive 31 miles each way to work and usually on reach 60 MPH or so. I only have 2 redlights during this trip. My car according to my records, over 20k miles, I have averaged 25.1 MPG.
Racer
Joined: Jul 2005
Posts: 467
Likes: 7
From: Fort Worth Texas
Safety Car
Joined: Feb 2002
Posts: 3,726
Likes: 368
From: Montoursville Pa
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
As previously posted, with a fully loaded trunk, a passenger and a slightly modded engine (headers, intake, exhaust, tuning, etc.), from NJ to FLA round trip, 28-29 mpg @ 75-80 mph. When cruising at the speed limit my mileage actually exceeded 30-31. After installing all the stuff I did, Doug at ECS tuned it. When I asked him how all the mods would affect mileage he said that after the tune it should go up slightly, which it did.
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW