2010 LS3 Gas Mileage Problem
Instructor
Joined: Nov 2009
Posts: 144
Likes: 2
From: Charlotte NC; Baton-Rouge LA NC and LA
09 Z06, with emngine mods, 66Kmi, 26-27 mpg at highway speeds
Greetings,
'09 Z06 here...., LS-7, 508 rwhp, bolt ons, blue printed fuel injectors, excellent computer tune, 345 -30-19 rear Invos.
66,479 mi a of today...many road trips (see profile). Fuel economy on the highway is... average 26.5-27.3 mpgat 80-85 mph...2000 rpm is 95 mph in 6th.
Even though Z06 is a litle lighter than the 2010 GS, you should be getting better fuel economy in my opinion on road trips...somethin' aint right IMHO.
Regards,
Duffy
'09 Z06 here...., LS-7, 508 rwhp, bolt ons, blue printed fuel injectors, excellent computer tune, 345 -30-19 rear Invos.
66,479 mi a of today...many road trips (see profile). Fuel economy on the highway is... average 26.5-27.3 mpgat 80-85 mph...2000 rpm is 95 mph in 6th.
Even though Z06 is a litle lighter than the 2010 GS, you should be getting better fuel economy in my opinion on road trips...somethin' aint right IMHO.
Regards,
Duffy
Heel & Toe
Joined: Jan 2009
Posts: 20
Likes: 1
From: Kernersville NC
Thanks all.... The 21.5 MPG was on a long highway trip - a trip from Vegas to Ely for the Silver State Classic. It was about 250 miles on pretty flat open highway - very little shifting involved. Speed limit the whole way (a ticket gets you disqualified from the event so everyone drives the speed limit on the way up there). I had also done a shorter trip recently and got about the same results. I spoke to the dealership mechanic - they will "call it in" to the factory but I don't get the feeling they are going to find anything. I was thinking about doing some coast down tests next to another LS3 car (coast from 80MPH to zero to check for excess drag or something binding up more than normal). Not sure what else to do here. It is significant enough to really bug me - I am going to the gas station twice as often as I was in my 2007 - it is my only car so it affects my monthly budgets, etc. I obviously didn't buy the car for just gas mileage - but I think it should at least get mid twenties on the road.
Racer
Joined: Jul 2010
Posts: 385
Likes: 2
From: AZ
mines getting bad gas mileage also 09 base A6 w/7.5k on it am im getting about 17mpg babying it around. i know it should be getting way better then that, there has to be something wrong a friend told me he saw some black smoke come out of my exhaust, the car is all stock. are dealers the only 1's who can do an alignment im new to owning a corvette.
Melting Slicks
Joined: Jul 2007
Posts: 2,063
Likes: 17
From: Lee's Summit MO
I keep checking the mileage on my GS every week when I fill the tank...
About 50/50 city and hiway, 17.3 mpg. And I don't flog it.
Best I've seen on the hiway (from DIC "instant" fuel economy) is 24.3 on flat hiway at 70 mph, no wind.
Lot of drag on those huge brakes.
About 50/50 city and hiway, 17.3 mpg. And I don't flog it.
Best I've seen on the hiway (from DIC "instant" fuel economy) is 24.3 on flat hiway at 70 mph, no wind.
Lot of drag on those huge brakes.
Le Mans Master
Joined: Dec 1999
Posts: 6,338
Likes: 2
From: Somewhere Texas
I've been complaining about mileage on my GS since I took delivery on it. I don't understand it either. I think it's the unsprung weight of the bigger tires and brakes. The LS3 does not have the TQ or the HP of the LS7 to pull the extra weight. This is my 13Th Corvette, and by far, the worst one for fuel mileage period.
TRR
TRR
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
not to belabor the point, but OP hasn't answered the question of when, or if he shifted into 6th gear. coming out of an A6 which automatically shifts to higher gear on reaching rpm/speed based on throttle position, many people in man trans cars either don't shift soon to top gear (6th) on the highway, or some don't shift at all to 6th.
that will affect MPG readings. also, I can't tell from profile if this is a coupe or convertible; if the latter, there is a definite difference in MPG from the coupe.
that will affect MPG readings. also, I can't tell from profile if this is a coupe or convertible; if the latter, there is a definite difference in MPG from the coupe.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Heel & Toe
Joined: Jan 2009
Posts: 20
Likes: 1
From: Kernersville NC
Took car back in yesterday. Alignment was way off, front and rear. They corrected it and I took a long test drive home over highway and side roads. I reset the mileage before leaving the dealership and after a 30 mile test drive, it is already 2 mpg better than the 200 mi highway trip last weekend. I'll be hitting the road again this weekend on a trip that the '07 routinely got 29-30 mpg. I'll give you an update on Monday.
Heel & Toe
Joined: Jan 2009
Posts: 20
Likes: 1
From: Kernersville NC
mines getting bad gas mileage also 09 base A6 w/7.5k on it am im getting about 17mpg babying it around. i know it should be getting way better then that, there has to be something wrong a friend told me he saw some black smoke come out of my exhaust, the car is all stock. are dealers the only 1's who can do an alignment im new to owning a corvette.
Racer
Joined: Jul 2010
Posts: 385
Likes: 2
From: AZ
Heel & Toe
Joined: Jan 2009
Posts: 20
Likes: 1
From: Kernersville NC
Thanks all.... The 21.5 MPG was on a long highway trip - a trip from Vegas to Ely for the Silver State Classic. It was about 250 miles on pretty flat open highway - very little shifting involved. Speed limit the whole way (a ticket gets you disqualified from the event so everyone drives the speed limit on the way up there). I had also done a shorter trip recently and got about the same results. I spoke to the dealership mechanic - they will "call it in" to the factory but I don't get the feeling they are going to find anything. I was thinking about doing some coast down tests next to another LS3 car (coast from 80MPH to zero to check for excess drag or something binding up more than normal). Not sure what else to do here. It is significant enough to really bug me - I am going to the gas station twice as often as I was in my 2007 - it is my only car so it affects my monthly budgets, etc. I obviously didn't buy the car for just gas mileage - but I think it should at least get mid twenties on the road.
Moderator
Joined: Dec 2002
Posts: 40,898
Likes: 4,351
From: Lakewood Ranch, FL
That's about what I get average on the interstate.
Race Director
Joined: Jul 2010
Posts: 10,548
Likes: 176
From: Upstate NY
I'm seeing the same thing. I got 30.6 mpg on a 200 mile highway trip the week before I traded my '07 coupe with MN6 and Z51 on a '10 GS coupe with MN6. With 1400 miles, it's averaging 22.5 on the same trip. Dealer says nothing is wrong but I'm not buying it. After I drive for 30-45 minutes, it seems like the drivetrain is binding or the brakes are dragging. At 70 mph in 6th gear, it's turning about 1750 rpm.
