Maximum Gas Mileage

[Travis Wills]

Standard GT doesn’t give me the average speed. No drafting. All I get is distance, avg mpg, and time

Distance divided by time is average speed. If you can take a picture of the info graphic then we can get all of the data from that alone.

 

[falanger]

Still my best single tank, since I don't road trip much and don't like long drives. Comfort mode most of the way, except when needing to pass or going uphill....

 

[MerlintheMad]

The single biggest factor affecting highway (defined as sans stoplights, or virtually so) average mpg is whether or not there are uphill stretches. For instance, twice I managed 30 plus mpg heading into TX. But coming back out, no way José: 27.something is the best I could get. Same going to LA from SLC: I can get very high, consistent 28 and 29 mpg; but the return trip I am lucky to break past 25 mpg.

 

[Travis Wills]

Still my best single tank, since I don't road trip much and don't like long drives. Comfort mode most of the way, except when needing to pass or going uphill....

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Where was this from and where was this going to. That is extremely good fuel efficiency for that average speed.

 

[Kimberly Lazarski]

To get that gas mileage I think you have to be going the speed limit of 55, no faster.

FWIW I used to get 32-33mpg on the highway in my ZR-1 (a '91 C4), cruising at 90mph (actually 93mph IIRC; that was the speed where I got peak mpg and would cruise at that speed for road trips - and no, I do not drive those speeds any more. Those days, that was my conservative driving. It wasn't unusual for me to be driving twice that on rural highways, when I was rich, young, and very foolish).

33mpg on road trips should be very doable in the Stinger with conservative driving with an appropriate tune, and not just an outlier.

 

[Snatchell]

I have gotten just shy of 34MPG before. It was a long drive with a mix of 55, 60, 65 and 70 MPH with almost no traffic. It was from Richmond, VA to Durham, NC. It was a mild summer day. I love the fact that my Stinger can be fast, but also efficient as I use it to travel for work sometimes. I think wheel alignment may have a lot to do with your MPG numbers on the highway, as well as the terrain and temperature. I also love that the hatchback allows me to pack in quite a bit of stuff needed to do my job when needed. I had a 2015 Sonata 2.0T that would get about the same highway MPG. I love this car!

 

[Travis Wills]

I have gotten just shy of 34MPG before. It was a long drive with a mix of 55, 60, 65 and 70 MPH with almost no traffic. It was from Richmond, VA to Durham, NC. It was a mild summer day. I love the fact that my Stinger can be fast, but also efficient as I use it to travel for work sometimes. I think wheel alignment may have a lot to do with your MPG numbers on the highway, as well as the terrain and temperature. I also love that the hatchback allows me to pack in quite a bit of stuff needed to do my job when needed. I had a 2015 Sonata 2.0T that would get about the same highway MPG. I love this car!

That is very good gas mileage. I live near Durham and I have traveled up to Richmond a number of times. I wonder if it is downhill from Richmond to Durham? That can actually make a significant difference especially when using the coasting feature.

 

[Snatchell]

That is very good gas mileage. I live near Durham and I have traveled up to Richmond a number of times. I wonder if it is downhill from Richmond to Durham? That can actually make a significant difference especially when using the coasting feature.

Also wind direction can be a factor. When I travel for work I always do the exact speed limit. I don't want a ticket far from home... Give it a shot next time and see what you get. You should get at least 30MPG. The winter gas is less efficient though so wait until summer to get the good MPGs. Also somewhere in NC there are gas stations with Ethanol-free gas. Some have no Ethanol and 100 octane, but that's pretty rare. There is an app called Pure Gas. I'd be interested in knowing if Ethanol-Free gas is a major factor as well...

BTW - Are you related to Rich and Becky Wills in Durham?

 

[nhsjpeterson]

I take the car's calculation with a grain of salt. When I actually fill up after a long trip and calculate MPG based on miles and gas added, it can be quite a bit less than what gets displayed on-screen.

 

[Travis Wills]

I take the car's calculation with a grain of salt. When I actually fill up after a long trip and calculate MPG based on miles and gas added, it can be quite a bit less than what gets displayed on-screen.

This is absolutely correct. It is almost always about 10% higher than what is actual.

However, the display is typically consistent so that if it says 33 mpg one day that is probably the same as 33 mpg another day or even perhaps the same as 33 mpg in another Stinger of the same model and trim level.

 

[Travis Wills]

BTW - Are you related to Rich and Becky Wills in Durham?

I don’t believe I am but Wills is not a very common last name. Willis seems to be much more common.

 

[Travis Wills]

FWIW I used to get 32-33mpg on the highway in my ZR-1 (a '91 C4), cruising at 90mph (actually 93mph IIRC; that was the speed where I got peak mpg and would cruise at that speed for road trips - and no, I do not drive those speeds any more. Those days, that was my conservative driving. It wasn't unusual for me to be driving twice that on rural highways, when I was rich, young, and very foolish).

33mpg on road trips should be very doable in the Stinger with conservative driving with an appropriate tune, and not just an outlier.

That doesn’t sound accurate. First I am not sure how 90 mph could be the most efficient speed unless you have an overdrive gear that can’t be engaged until 90 mph. Even if that is the case then that just doesn’t sound reasonable. How many gears were in that car?

Also 33 mpg instantly or 33 mpg average? No way that car could average 33 mpg over any significant distance that wasn’t downhill.

 

[Rob M]

I'd be interested in knowing if Ethanol-Free gas is a major factor as well...

They say gasoline produces 1/3 more energy than the same volume of ethanol. So E10 gasoline (10% ethanol) should result in a little more than 3% less fuel economy. Right around 1 mpg less on the highway.

 

[Rob M]

That doesn’t sound accurate. First I am not sure how 90 mph could be the most efficient speed unless you have an overdrive gear that can’t be engaged until 90 mph. Even if that is the case then that just doesn’t sound reasonable. How many gears were in that car?

Also 33 mpg instantly or 33 mpg average? No way that car could average 33 mpg over any significant distance that wasn’t downhill.

They were 6spds, and 6th gear had a 0.5 gear ratio (Stinger is 0.565 in 8th) and weighed less than 3500#, so they had deceptively good fuel economy when cruising fast and gently in "overdrive". Not sure if 33mpg would be routine, and not sure whether 93mph would result in the most efficiency, but it would be loping along at just a little over 2000rpm at that speed. You wouldn't even bother shifting into 6th gear unless you were going at least 60 or 70 mph. Keep in mind that the EPA mileage rating test schedules would have forced the ZR1 to stay in no higher than 5th gear during testing, so the 23mpg hwy rating was in no way indicative of the achievable gas mileage in 6th gear on the open highway.

 

[SafetyPilotCal]

That doesn’t sound accurate. First I am not sure how 90 mph could be the most efficient speed unless you have an overdrive gear that can’t be engaged until 90 mph. Even if that is the case then that just doesn’t sound reasonable. How many gears were in that car?

Also 33 mpg instantly or 33 mpg average? No way that car could average 33 mpg over any significant distance that wasn’t downhill.

On a really flat (or otherwise favorable) road and the right temperature, I wouldn't entirely rule it out. I can pull off 29-30 MPG pretty easily cruising at 84 MPH (cruise set at 9 over) in my C5 here in TX. Slippery car, turning less than 2k RPM in 6th gear, and the LS1 isn't exactly working hard to propel it down the road. I'm not familiar with the fueling and DFCO tables on the LT5 in a C4 ZR1, but it's possible it's sitting at just the right load to be barely adding fuel when touching the pedal and then cutting off fuel on decel.

I pulled over 30 MPG driving from Pittsburgh to Dayton once in a '97 Grand Prix GTP with the cruise set at 70 and only a mildly tweaked tune.

 

[Travis Wills]

Wind resistance varies exponentially with speed. At higher and higher speeds wind resistance becomes the primary factor and at much higher speeds it becomes the ONLY relevant factor.

Honestly, I would need to see some sort of evidence to believe the C4 Corvette achieved its best mpg above 90 MPH. That is really hard to believe.

 

[P22Tyler]

I got 40+ once....

Of course it was coming down the canyon gliding pretty much the entire way .

 

[Kimberly Lazarski]

That doesn’t sound accurate. First I am not sure how 90 mph could be the most efficient speed unless you have an overdrive gear that can’t be engaged until 90 mph. Even if that is the case then that just doesn’t sound reasonable. How many gears were in that car?

Also 33 mpg instantly or 33 mpg average? No way that car could average 33 mpg over any significant distance that wasn’t downhill.

Rob covered the gearing accurately. 6th gear was very tall and the C4-era ZR1 had a tall final gear ratio as well.

Rockland, MA to Hanover, PA and back through MA/CT/NY/Northern PA with lots of up and down mountains but using cruise control most of the way and in neutral down the very long descents, I got 33mpg average doing that trip multiple times on the stock tune (I would swap out the PROM when I got there). Prior to moving to Rockland, MA I had a 77mi commute to work and regularly exceeded 30mpg combined including the daily Route 128 fustercluck on days I drove that car conservatively. Most days I got closer to 18mpg combined driving it like I stole it. It was hard to get truly bad economy in that car on the stock tune. On the custom PROM Jeremy from FasterPROM made for me I would get only about 25mpg combined on a very good day I was well-behaved and usually closer to 20mpg. The LT5 was an amazing engine in its time. Keep in mind it had 16 intake runners (8 primary 8 secondary) and 16 fuel injectors (8 pri 8 sec), and staying out of the secondaries delivered V6 performance and near-I4 economy.

A Look At The C4 ZR-1's Jewel-Like, All-Aluminum DOHC LT5 Engine

Over 30mpg should be very achievable on the Stinger with its direct-inject engine and using cruise control.

 

[MerlintheMad]

Over 30mpg should be very achievable on the Stinger with its direct-inject engine and using cruise control.

Lol. Not happening except as a fluke. Oh, and being more talented in the driving than most others. I am only average-smaverage, myself. I need a bit of help in the driving conditions in order to get 30 mpg.

 

[falanger]

Just returned from holiday road trip and here's my best tank. Oddly, this tank was lower than my previous best which was achieved using Comfort, which once again makes me question the effectiveness of Eco mode on the highway:

Still my best single tank, since I don't road trip much and don't like long drives. Comfort mode most of the way, except when needing to pass or going uphill....

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