[Z06] Amazing MPG
07-05-2012, 07:17 PM
#1
Melting Slicks
Thread Starter
Amazing MPG
Recently took a 300 mile trip. Temps were hovering near 100 so had the a/c cranked and assumed that mpg would take a hit. Had the cruise set at 65 and winds were calm, mostly flat terrain. When I checked the mpg when I reached my destination I couldn't believe it - the DIC showed 33.6! 
I make this trip 3-4 times a year and normally get around 29-30, with a previous best of 31.5. Guess the Z06 likes the heat, at least for mpg. Original owner of an 06 with 72k trouble free miles on it (even has original battery) and it just keeps amazing me.
I make this trip 3-4 times a year and normally get around 29-30, with a previous best of 31.5. Guess the Z06 likes the heat, at least for mpg. Original owner of an 06 with 72k trouble free miles on it (even has original battery) and it just keeps amazing me.
07-05-2012, 09:02 PM
#3
Instructor
Member Since: May 2011
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I had a similar thing happen years ago - at least this is what I think you experienced.
I'm guessing you started out in the morning with a full tank. I'm also guessing the car was garaged overnight, and the garage was "relatively" cool, like not much above 70 degrees.
When you hit the heat, the gas in the tank expanded as you were driving, and you may have noticed that it seemed like the gauge was stuck towards full. That's because as you were burning gas, the gas in the tank was expanding in those 100 degree temps.
Kinda fun when it happens....
I'm guessing you started out in the morning with a full tank. I'm also guessing the car was garaged overnight, and the garage was "relatively" cool, like not much above 70 degrees.
When you hit the heat, the gas in the tank expanded as you were driving, and you may have noticed that it seemed like the gauge was stuck towards full. That's because as you were burning gas, the gas in the tank was expanding in those 100 degree temps.
Kinda fun when it happens....
07-05-2012, 09:40 PM
#5
Le Mans Master
There no way a car that's rated at 18 city and 24mpg on the highway is going to get 33mpg. Your DIC is off or you're running way too lean....pray for the first scenario.
Last edited by Turbooo2u; 07-05-2012 at 10:14 PM.
07-05-2012, 10:41 PM
#6
Let me chime in on a recent 2000 mile trip from West Texas and once around Colorado and back. Early June, temps in the 90's mostly, flat lands and Mountains. City/Highway/75-80 on most highways. 28mpg. This is my economy car.
07-05-2012, 11:08 PM
#8
Melting Slicks
Thread Starter
I had a similar thing happen years ago - at least this is what I think you experienced.
I'm guessing you started out in the morning with a full tank. I'm also guessing the car was garaged overnight, and the garage was "relatively" cool, like not much above 70 degrees.
When you hit the heat, the gas in the tank expanded as you were driving, and you may have noticed that it seemed like the gauge was stuck towards full. That's because as you were burning gas, the gas in the tank was expanding in those 100 degree temps.
Kinda fun when it happens....
I'm guessing you started out in the morning with a full tank. I'm also guessing the car was garaged overnight, and the garage was "relatively" cool, like not much above 70 degrees.
When you hit the heat, the gas in the tank expanded as you were driving, and you may have noticed that it seemed like the gauge was stuck towards full. That's because as you were burning gas, the gas in the tank was expanding in those 100 degree temps.
Kinda fun when it happens....
I have checked the DIC against the math several times in the past and it has always been within 1 or 2 mpg. So even if the DIC is optimistic by a couple of mpg, it's still amazing that I got over 2 mpg more than I've ever got before and especially in those conditions. And I don't think I'm running lean - got on it pretty good a few times after the trip and it still has the power and no knock.
07-05-2012, 11:32 PM
#9
Race Director
Just like Bonneville, you have to back it up with a return run. What was your miles/gallon on the way back home? If you were going north to south, you were going downhill and don't forget the wind factor.
07-05-2012, 11:36 PM
#10
The Consigliere
Member Since: May 2006
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That is a high number indeed.
Never thought about the gasoline expanding as it warms, but it makes sense.
Never thought about the gasoline expanding as it warms, but it makes sense.
07-06-2012, 05:54 AM
#11
Recently took a 300 mile trip. Temps were hovering near 100 so had the a/c cranked and assumed that mpg would take a hit. Had the cruise set at 65 and winds were calm, mostly flat terrain. When I checked the mpg when I reached my destination I couldn't believe it - the DIC showed 33.6!
I make this trip 3-4 times a year and normally get around 29-30, with a previous best of 31.5. Guess the Z06 likes the heat, at least for mpg. Original owner of an 06 with 72k trouble free miles on it (even has original battery) and it just keeps amazing me.
I make this trip 3-4 times a year and normally get around 29-30, with a previous best of 31.5. Guess the Z06 likes the heat, at least for mpg. Original owner of an 06 with 72k trouble free miles on it (even has original battery) and it just keeps amazing me.
07-06-2012, 08:59 AM
#14
Instructor
Member Since: May 2008
Location: Orange Park Florida
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I have taken several 300 to 700 mile trips and my real mileage (not DIC)consistantly is around 25-26 mpg. I drive at around 75-78 mph with the cruise on. My mods are a beehive air intake and a conservative tune.
I had an 08 6spd manual LS3 coupe and got over 30 mpg several times.
I am pretty happy with anything over 25 mpg for a car with this kind of power. I remember my hot rods from the 60's and 70's getting 5-6 mpg on a good day, and they weren't as fast or comfortable. Gotta love the
ZO6!
I had an 08 6spd manual LS3 coupe and got over 30 mpg several times.
I am pretty happy with anything over 25 mpg for a car with this kind of power. I remember my hot rods from the 60's and 70's getting 5-6 mpg on a good day, and they weren't as fast or comfortable. Gotta love the
ZO6!
07-06-2012, 09:38 AM
#16
Burning Brakes
I don't think I buy into the theory that the DIC is less accurate than my math calculations.
If I calculate the mileage by hand I use the gallon figure on the gas station pump and the trip odometer in the car.
I believe the fuel consumption figured by the computer in the car and fed to the DIC for it to make it's calculation is probably just as accurate, and maybe more accurate, than the gauge on the gas pump at the station. I have read that tests show the pumps at the gas station to be notoriously inaccurate.
The two mileage figures may disagree but I think it is indeterminate as to which one is more accurate.
Believe what you want
If I calculate the mileage by hand I use the gallon figure on the gas station pump and the trip odometer in the car.
I believe the fuel consumption figured by the computer in the car and fed to the DIC for it to make it's calculation is probably just as accurate, and maybe more accurate, than the gauge on the gas pump at the station. I have read that tests show the pumps at the gas station to be notoriously inaccurate.
The two mileage figures may disagree but I think it is indeterminate as to which one is more accurate.
Believe what you want
07-06-2012, 10:17 AM
#17
Race Director
I've had the same experience in my C5 coupe, and the C6Z. DIC is a bit generous..but eh..still not bad considering we are talking about a 505 HP car.. even getting 22mpg on the Hwy ain't too shaby.
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07-06-2012, 11:19 AM
#19
If the gas pumps can be inaccurate, so can the DIC. lol
I fill up almost at the same time when I need gas, and based off of mileage I am always with in 1/2 a gallon of topping off. Each time I am off 2-5mpg from the DIC, coincidence? I don't think so.
But this isn't really a debatable topic. To each their own.
I fill up almost at the same time when I need gas, and based off of mileage I am always with in 1/2 a gallon of topping off. Each time I am off 2-5mpg from the DIC, coincidence? I don't think so.
But this isn't really a debatable topic. To each their own.
07-06-2012, 11:43 AM
#20
I don't think I buy into the theory that the DIC is less accurate than my math calculations.
If I calculate the mileage by hand I use the gallon figure on the gas station pump and the trip odometer in the car.
I believe the fuel consumption figured by the computer in the car and fed to the DIC for it to make it's calculation is probably just as accurate, and maybe more accurate, than the gauge on the gas pump at the station. I have read that tests show the pumps at the gas station to be notoriously inaccurate.
The two mileage figures may disagree but I think it is indeterminate as to which one is more accurate.
Believe what you want
If I calculate the mileage by hand I use the gallon figure on the gas station pump and the trip odometer in the car.
I believe the fuel consumption figured by the computer in the car and fed to the DIC for it to make it's calculation is probably just as accurate, and maybe more accurate, than the gauge on the gas pump at the station. I have read that tests show the pumps at the gas station to be notoriously inaccurate.
The two mileage figures may disagree but I think it is indeterminate as to which one is more accurate.
Believe what you want