Mpg
Race Director
Joined: Mar 2010
Posts: 16,871
Likes: 5,329
From: T-Town WA
2016 C6 of Year Finalist
I have made many 1500+ mile trips and cruise at 16-1700 in 6th all day. If I'm in hilly terrain I will run in the 18-2000 bracket...or more if conditions require. If I need to press hard on the foot feed I want some RPM's up before I start.
Le Mans Master
Joined: Feb 2014
Posts: 5,463
Likes: 1,138
From: Chino CA
- RPM's MPG's & MPH are all closely related measures. And you are correct that at 70 mph you are below a 2000 rpm threshold. That's my concern. As a first time owner, I have been concerned about keeping the rpm's at or near 2000 for the optimal treatment of the engine, not so much concerned about mph. If you are really going to enjoy this vehicle then you need to feed it the fuel required. You could feed it lower octane fuel to save money but performance will suffer. Maybe that's a topic for another discussion. My concern here is with an emphasis on rpms.
Race Director
Joined: Dec 2007
Posts: 19,574
Likes: 167
From: Frederick, MD
We have a mountain pass just east of Salt Lake City called Parley's Summit. It goes from 4300 to around 8400 feet in elevation. My 13 GS with Auto will maintain 6th gear at around the speed limit with the engine around 1700 rpm. It has no trouble maintaining that speed or even increasing it without shifting down. Of course more throttle means it will shift down and you will accelerate without a problem. C6 just does not care about hills.
Even our 18 Equinox that has a 4 banger turbo may shift down to 8th gear (from 9th), also 7th at times. It doesn't feel like it is lugging. I had a 12 Chrysler 300 Hemi AWD before and cruising at 75 mph was around 2300 rpm.
I don't worry about MPG with the Vette but cruising at 80ish around here in Utah will net about 22-23 MPG. I have pushed it hard before when out with some "exotic" cars and the Italian cars needed to fill up with gas twice as much.
Even our 18 Equinox that has a 4 banger turbo may shift down to 8th gear (from 9th), also 7th at times. It doesn't feel like it is lugging. I had a 12 Chrysler 300 Hemi AWD before and cruising at 75 mph was around 2300 rpm.
I don't worry about MPG with the Vette but cruising at 80ish around here in Utah will net about 22-23 MPG. I have pushed it hard before when out with some "exotic" cars and the Italian cars needed to fill up with gas twice as much.
Team Owner
Joined: May 2004
Posts: 82,175
Likes: 1,319
From: McKinney TX
St. Jude Donor '21-'22-'23-'24
My C6s usually averaged about 27 MPG at 75-77 MPH on the interstate for about 55 miles between Nashville and Manchester. 14-15 MPG in town with a moderate amount of stop-n-go traffic.
Advanced
Joined: Jun 2014
Posts: 82
Likes: 10
From: St. Louis Missouri
I'm averaging around 16.5 mpg in my 2008 six-speed with a commute that is at least 50% highway. I suppose I like to hear the engine too much or something. While I'm sure I could average over 20 mpg, I wouldn't like driving the car and would sell it.
Drifting
Joined: Feb 2017
Posts: 1,752
Likes: 699
From: Covington KY
2022 C6 of the Year Finalist - Unmodified
'05 LS2 Z51 M6 currently registering 19.3 mpg in combined city/highway driving but more in the city. I have a Cobalt 4 banger that is my daily on mostly the same roads and it is averaging a little under 24 mpg, which one would you rather drive? I'll take the 'vette! And can't you just listen to the engine and tell when it is winding out, lugging down or in the sweet spot, it's not rocket science.
Burning Brakes
Joined: Sep 2012
Posts: 988
Likes: 414
From: Marietta GA
I have taken mine on a few longer drives. I have found that, and this does not make sense at first, I get better mileage at 80mph than 75mph. At 75mph i'm seeing about 1800 rpm and at 80 I see about 2000 rpm. The best I can figure is that is has something to do with the torque / HP power curve and that just that little bump in RMP gets it into a slight better range and the engine/drive trail runs more economically.
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Instructor
Joined: Feb 2011
Posts: 108
Likes: 0
From: Tacoma Washington
Just drove from Pocatello Idaho to Tacoma Washington straight for 12 hours and got 29.9 miles to the gallon with a max speed in Idaho of around 85 and a low in Washington of around 65.
Many places in the middle with construction and fires to slow me down in some areas to around 40-45.
all in all I was very pleased with the results.
2007 convertible with top up all the way home.
Also just FYI I just bought this car and drove it home.
Many places in the middle with construction and fires to slow me down in some areas to around 40-45.
all in all I was very pleased with the results.
2007 convertible with top up all the way home.
Also just FYI I just bought this car and drove it home.
Pro
Joined: Mar 2018
Posts: 660
Likes: 63
From: Fresno CA
Seriously.
I wish I got 16mpg. My commute is about 50/50 highway/city and I'm getting an average of 10.9mpg on this tank (usually hovers between 9-12). Every drive for me is a spirited drive, though.
I bought this car for a reason, ya know. '08 mn6 ls3 supercharged but otherwise stock.
Team Owner
Joined: Mar 2014
Posts: 21,631
Likes: 1,144
From: Below the bottom of Berby Hollow, NYS
Safety Car
Joined: Jan 2011
Posts: 4,959
Likes: 526
I think they were trying to ask if it was hard on your engine to go too slow in any given gear. Back in the day we would call it lugging the motor.......or something like that. I think the only people that have to worry about it these days are the owners of harleys big twins....lOL
Drifting
Joined: Sep 2016
Posts: 1,260
Likes: 324
From: Florida
Team Owner
Joined: Mar 2014
Posts: 21,631
Likes: 1,144
From: Below the bottom of Berby Hollow, NYS
Will it die like a horse that doesn't get enough fuel? 
Thread Starter
6th Gear
Joined: Jul 2015
Posts: 6
Likes: 0
From: New Palestine Indiana
OK, OK, let's see if I can clarify my question. It should be apparent that a Corvette is not generally purchased or even designed with mpg in mind. It is, however, capable of obtaining some pretty remarkable numbers. In order to achieve those numbers, I would suspect that the car is being driven with some pretty low rpm's. I question if driving to obtain those remarkable numbers might be harmful. Let's visualize for a moment that you are driving around town at 40 - 45 mph. I normally try to keep the rpm's around 2000 rpms. Perhaps a little less but certainly not much as it feels like it might be lugging the engine. Cruising at interstate speeds I can see holding rpm's a little less than 2000 because you are often not accelerating or making demands on the engine. Forget mpg, what is the best technique for the car? Automatics don't worry about these issues but those of us with sticks have greater control and more responsibility for driving correctly. I am looking for reasoned opinions.
Pro
Joined: Oct 2015
Posts: 524
Likes: 76
From: El Paso Texas
I don't think they ran the RPMs dangerously low just to get a little better mileage. Manual transmission cars have always used slightly less gas than automatics because no power is lost in the torque converter. If you drive a C6 automatic, you will notice it shifts through the gears to the highest gear possible without wasting any time. The automatics actually keep the RPMs too low around town - in my opinion. If you need to accelerate very much, it has to shift down 3 gears. Unless you feel the engine bucking or shaking under load, you are not lugging it. These engines will take a tremendous beating and still last a long time. I purposely tried to tear up 350 V8 in my 78 chevy truck and it just kept going.
Last edited by montman; Jul 31, 2018 at 01:52 PM.
Pro
Joined: Mar 2018
Posts: 660
Likes: 63
From: Fresno CA
OK, OK, let's see if I can clarify my question. It should be apparent that a Corvette is not generally purchased or even designed with mpg in mind. It is, however, capable of obtaining some pretty remarkable numbers. In order to achieve those numbers, I would suspect that the car is being driven with some pretty low rpm's. I question if driving to obtain those remarkable numbers might be harmful. Let's visualize for a moment that you are driving around town at 40 - 45 mph. I normally try to keep the rpm's around 2000 rpms. Perhaps a little less but certainly not much as it feels like it might be lugging the engine. Cruising at interstate speeds I can see holding rpm's a little less than 2000 because you are often not accelerating or making demands on the engine. Forget mpg, what is the best technique for the car? Automatics don't worry about these issues but those of us with sticks have greater control and more responsibility for driving correctly. I am looking for reasoned opinions.