Txaz

We had a base 2008 and consistently got 30 mpg on the highway at 75-80 (seemed to be the best speed for the best Mpg).
Question to you is, in a stock Vette, what's the best mileage you've gotten?

JoesC5

We just got back from a 2300 miles road trip to southern Colorado and northern New Mexico. I was driving my 2009 C6 Z06 and one of the cars in our group was a C7 Z51 M7.

We both reset our trip odometers when we left home and at around 2000 miles we compared our gas mileage. Remember that we were traveling together, same roads, weather, speeds, gas, etc. Enough fill ups to get a good average gas mileage reading under many types of driving.

I had a 27.6 MPG average (DIC) and the C7 had a 29.1 MPG average(DIC) at the same point in time. My M6 has a .50 6th gear and the C7 Z51 has a .48 7th gear. And we were running at around 80 MPH when on the Interstate. Very little difference in engine RPM between the two cars when cruising at 80 MPH. For the entire trip, I used approximately 4 gallons more gas(or around $13-$14). The C7 has a .29 Cd and my Z06 has a .34 Cd, so he was slipping through the air a little more easier than I was.

Aflyer

I didn't buy either car for Gas Mileage, but it sure is fun to share the numbers. Especially with my wife who gets worse mileage with her Grand Cherokee, V6 8 speed automatic.

I had a 2003 M6 and could get 30 on longer trips, and got about 24 around town & back & forth to work. All these numbers with DIC.
My C7, Z51 M7 is getting 25 everyday driving, and I did get 32.7 on a trip from NC to NY, the car has just hit 6,000 miles.

SilversledC7

Dash currently shows last 50 mile average of 33.0 MPG. Picture was taken about 5 seconds before reaching this..

John Ulrich

bob guzzy

I'm quite pleased with 24 in the city and 29 highway, I like putting my foot in it.

C7pimp

My best 50 mile stretch is 39.6mpg in 7th gear, Eco mode at about 72mph.


I have a base 1LT which is considerably lighter than a 3LT Z51.

autoxnut

Here is my best in my 2014 Z51 on vacation after I left the Ron Fellow Driving School.

nmerhaut

What mode was the C7 using for this? Thanks

JoesC5

econ. I'm sure that if the trip had been nothing but 100% flat, smooth, four lane with no traffic, etc., the delta between us would have been higher, but I was trying to point out a real world driving comparison done at the exact same time, conditions, speeds, etc..

Short runs with very good conditions and my DIC shows 32-33 MPG on my C6 Z06, but I can't maintain that for a long run, under varying conditions.

AT one point, the new diesel Cruze with our group recorded 52 MPG, but for the entire trip, it was mid 40's.

tail_lights

20.1

Butttt, It's the first fill and I'm breaking her in so lots of gears changes and starts/stops. Honestly surprised it was that good

Down8

32.5 best 25
30+ best 50
22.9 best 400

Daily driver, with a couple long-ish trips here and there. A6/Z51, 7000+miles, cruise 75-80 when not in traffic.

-bZj

dodgersphc

34.1 mpg, 1800 mile road trip from Washington to California and back, ECON mode the whole time in an M7.

tblu92

I have deleted my DOD and have tuned my car with EFILIVE----It averages 30-31 MPG at 65 MPH--- When I had the DOD operational it would go as high as 34-36 MPG--
To me it is not worth that little extra mileage when using DOD-----If you understand how DOD works in my opinion it is a detriment to long life of the engine--Solenoids shut oiling off to the lifters-to prevent the valves from opening--However the lifter are still running over the camshaft--GM has had several lifter failures on Silverdo's with DOD which require a complete engine rebuild when they fail--Seems like the only lubrication the lifters get in 4 cyl mode is by splash---It's a sports/muscle car--and should be used for that reason---Only reason they put DOD on a Corvette now is to meet the tough CAFE standards of fuel mileage---We should thank GM for putting it on there so they can make us such a wonderful car---But a serious enthusiast will not ever use the DOD --That's why GM made it tunable to turn it off easily and in stock mode by driving with the paddle shifter

JoesC5

I don't think you fully understand how the lifters operate on the AFM system. The solenoids direct oil to retract the locking shot pins in those eight lifters so the telescoping lifters can collapse when in 4 cylinder mode. That (acting as a hydraulic)oil has nothing to do with the oil that is fed to the lifters for their normal operation, that is also fed through the pushrods to lubricate the rocker arms, etc.

When not operating in 4 cylinder mode, the solenoid closes shutting off the (hydraulic) oil to the locking shot pin, and the internal spring in the lifter holds the locking pin engaged so the telescoping lifter acts as a normal lifter.

TEXHAWK0

32.9 MPG in 6th gear with cruise control set to 75.
Probably will never try ECO mode.. It just ain't right.

Duck Hunter

My best MPG was on a segment of the trip driving home from Bowling Green in our 2015 M7. 34 mpg in the 350 miles from Spokane to Bellingham with the Cruise set at 70 to 75 mph in touring mode! Since then, I'm having too much fun to do much better than 23 in mixed driving!

JoesC5

That's a great number(34mpg). What was the number for the entire trip?

tblu92

That doesn't make any sense ----If the lifter is locked so it acts as a normal lifter--then the valve are still opening and closing !!!--All I can tell you is that in DOD mode--lifter often fail --for lack of lubrication--ask yourself what would cause that ?? Only reasonable assumption is that the lubrication is not adequate while in DOD----
Are you trying to say the valves are held open ?? in DOD mode

tail_lights

25.2 average from today's fill up, manually calculated. 700 miles on the car. Still breaking in I'm sure, I expect better.