[Z06] Gas mileage is NOT important for a Z06, or is it?
07-26-2016, 06:02 PM
#1
Gas mileage is NOT important for a Z06, or is it?
I would like to look at this question from the standpoint of street driving and track driving.
For the street the C6 Z06 gets 15 mpg city and 24 mpg highway. The C7 Z06 automatic gets 13/21(2014-2015) 13/23 mpg (2016) and the manual gets 15/22 mpg. https://www.fueleconomy.gov/feg/printGuides.shtml Most of the time each new car generation gets better mileage than the previous, but not the C7 Z06. The reason why has to do with changes people asked for like upgraded interior, better seats, open air experience, etc. The engineers needed to meet new safety regulations and add performance features like the electronic deferential and rev matching downshift, etc. But all this stuff adds weight and to overcome this weight they decided to go to a supercharged engine, which adds even more weight and the parasitic loss from supercharging hurts gas mileage. To improve mileage they added variable valve timing, more transmission speeds, and cylinder deactivation which added a lot more parts and reengineering existing parts which in turn adds weight. So the engineers got themselves into a vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight and so the C7 Z06 is 300 to 350 pounds more than the C6 Z06 at a time when other GM cars are losing that much weight.
Now how does gas mileage effect track driving from the standpoint of cost, heat, and the driving experience. Let’s take a look at what it costs to run a Z06 for a day at the track. In the hands of an expert driver the C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg. Let’s assume that you fill up just before you get to the track; you have half a tank, so you put in 9 gallons to give you a full tank. For those of you who get 5 sessions at 20 minutes (27 miles) per session; C6 Z06 would use 4.5 gallons per session, you fill up after 3 sessions (13.5 gallons), you run session 4 and 5 which leaves you 9 gallons in your tank to get home. C7 Z06 would use 7.7 gallons per session, you fill up after session 2 (15.4 gallons), you fill up after session 4 (15.4 gallons), you run session 5 which leaves you 10.3 in your tank to get home. For the C7 Z06 I am going to make the assumption that you’re very lucky that it does not overheat during any of the sessions because you did the track preparation in the owner’s manual and it is a very cool day. I am going to use California gas prices; $3.00 outside the track, $6.00 at the track. For the C6 Z06 total gas cost is $108.00 (9 * $3.00 + 13.5 * $6.00) for a day at the track. For the C7 Z06 total gas cost is $211.80 (9 * $3.00 + 15.4 * $6.00 + 15.4 * $6.00) for a day at the track. It costs the C7 Z06 owner almost 2X more for a day at the track if the car can run the whole time.
Now let’s look at gas mileage from the standpoint of heat generated. The C7 Z06 is using 71% more gas than the C6 Z06 (C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg). I am not sure if I can say that translates directly into 71% more heat the cooling system has to dissipate, but I think we all can agree it is substantially more heat that the cooling system has to dissipate. Now it should be painfully obvious why the C7 Z06 has such an overheating problem. On top of that the C7 Z06 has the intercooler radiator setting in front of the engine radiator. Not only does the intercooler radiator slightly restrict airflow to the engine radiator but it is heating up the air before the engine radiator gets it. After market Radiator manufactures have tried higher capacity radiators with little to no effect because of the issues I have mentioned above with the intercooler radiator and the large belly pan further restricting airflow. The only way a higher capacity radiator can work is if there is a sufficient flow of cool air. LG and GSpeed are putting additional openings in the front of the car with separate air inlets for each radiator/cooler. I think they will eventually be successful in solving the cooling problem, but unfortunately they will have created 3 new problems. The new air inlets will create substantially more drag and lift and the additional radiators/coolers with add weight in front of the front tires skewing the balance of the car. The Chevrolet engineers are no dummies and I am sure they have already looked at this approach and discarded it because of all the new problems that it creates. So what you will see from Chevrolet are more band aids like the rear mounded cooler, power steering scoop, and larger hood openings in the 2017 Z06. None of which totally solve the problem. This is another example of the vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight>Cooling solutions>Weight has done to the C7 Z06.
You could take a C5 Z06 and C6 Z06 right from the show room to the track and run HPDE sessions all day with no problems. Unfortunately that is not the case with the C7 Z06 even though it is sold as a track car. Turning one fast lap is meaningless when each additional lap is slower and then you overheat. A person cannot test/gauge/improve their driving ability with a car that does not provide consistent performance. This is why the C5 Z06 and C6 Z06 are truly great track cars.
So to make the C7 appeal to as many people as possible particularly those asking to be “comfortable” and have an “open air experience” we ended up with a dumbed down, over weight, overheating, compromised Z06. So be careful what you ask for, you may get it!
------------------------------------------- 8/20/2018 Update ------------------------------------------------------------------------
Now that I have data on the C7 ZR1 I thought I would update this post. A C7 ZR1 is the heaviest Corvette ever. With M7 and Track Performance Package (ZTK – High Wing) and no fuel it is 3501 pounds, with full fuel 3615, with 3ZR (Heated seats, PDR, Premium audio, etc.) 3647 pounds. The good news is that at Summit Point Motorsports Park it did not overheat and it recorded consistent lap times on a 30 minute run. https://www.corvetteforum.com/forums...ay-report.html The bad news is that it got only 2.9mpg on 93 octane and most of the time the driver was not any faster than when he drove a C7 Z06 at this track.
As an interesting aside, NASCAR Cup cars with 5.8 Liter engines producing 850 horsepower get 4.5mpg at Watkins Glen. Supercharging may be great at the dragstrip but for road racing it is very inefficient from parasitic HP loss and heat generated that requires additional coolers which adds drag and weight.
For the street the C6 Z06 gets 15 mpg city and 24 mpg highway. The C7 Z06 automatic gets 13/21(2014-2015) 13/23 mpg (2016) and the manual gets 15/22 mpg. https://www.fueleconomy.gov/feg/printGuides.shtml Most of the time each new car generation gets better mileage than the previous, but not the C7 Z06. The reason why has to do with changes people asked for like upgraded interior, better seats, open air experience, etc. The engineers needed to meet new safety regulations and add performance features like the electronic deferential and rev matching downshift, etc. But all this stuff adds weight and to overcome this weight they decided to go to a supercharged engine, which adds even more weight and the parasitic loss from supercharging hurts gas mileage. To improve mileage they added variable valve timing, more transmission speeds, and cylinder deactivation which added a lot more parts and reengineering existing parts which in turn adds weight. So the engineers got themselves into a vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight and so the C7 Z06 is 300 to 350 pounds more than the C6 Z06 at a time when other GM cars are losing that much weight.
Now how does gas mileage effect track driving from the standpoint of cost, heat, and the driving experience. Let’s take a look at what it costs to run a Z06 for a day at the track. In the hands of an expert driver the C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg. Let’s assume that you fill up just before you get to the track; you have half a tank, so you put in 9 gallons to give you a full tank. For those of you who get 5 sessions at 20 minutes (27 miles) per session; C6 Z06 would use 4.5 gallons per session, you fill up after 3 sessions (13.5 gallons), you run session 4 and 5 which leaves you 9 gallons in your tank to get home. C7 Z06 would use 7.7 gallons per session, you fill up after session 2 (15.4 gallons), you fill up after session 4 (15.4 gallons), you run session 5 which leaves you 10.3 in your tank to get home. For the C7 Z06 I am going to make the assumption that you’re very lucky that it does not overheat during any of the sessions because you did the track preparation in the owner’s manual and it is a very cool day. I am going to use California gas prices; $3.00 outside the track, $6.00 at the track. For the C6 Z06 total gas cost is $108.00 (9 * $3.00 + 13.5 * $6.00) for a day at the track. For the C7 Z06 total gas cost is $211.80 (9 * $3.00 + 15.4 * $6.00 + 15.4 * $6.00) for a day at the track. It costs the C7 Z06 owner almost 2X more for a day at the track if the car can run the whole time.
Now let’s look at gas mileage from the standpoint of heat generated. The C7 Z06 is using 71% more gas than the C6 Z06 (C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg). I am not sure if I can say that translates directly into 71% more heat the cooling system has to dissipate, but I think we all can agree it is substantially more heat that the cooling system has to dissipate. Now it should be painfully obvious why the C7 Z06 has such an overheating problem. On top of that the C7 Z06 has the intercooler radiator setting in front of the engine radiator. Not only does the intercooler radiator slightly restrict airflow to the engine radiator but it is heating up the air before the engine radiator gets it. After market Radiator manufactures have tried higher capacity radiators with little to no effect because of the issues I have mentioned above with the intercooler radiator and the large belly pan further restricting airflow. The only way a higher capacity radiator can work is if there is a sufficient flow of cool air. LG and GSpeed are putting additional openings in the front of the car with separate air inlets for each radiator/cooler. I think they will eventually be successful in solving the cooling problem, but unfortunately they will have created 3 new problems. The new air inlets will create substantially more drag and lift and the additional radiators/coolers with add weight in front of the front tires skewing the balance of the car. The Chevrolet engineers are no dummies and I am sure they have already looked at this approach and discarded it because of all the new problems that it creates. So what you will see from Chevrolet are more band aids like the rear mounded cooler, power steering scoop, and larger hood openings in the 2017 Z06. None of which totally solve the problem. This is another example of the vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight>Cooling solutions>Weight has done to the C7 Z06.
You could take a C5 Z06 and C6 Z06 right from the show room to the track and run HPDE sessions all day with no problems. Unfortunately that is not the case with the C7 Z06 even though it is sold as a track car. Turning one fast lap is meaningless when each additional lap is slower and then you overheat. A person cannot test/gauge/improve their driving ability with a car that does not provide consistent performance. This is why the C5 Z06 and C6 Z06 are truly great track cars.
So to make the C7 appeal to as many people as possible particularly those asking to be “comfortable” and have an “open air experience” we ended up with a dumbed down, over weight, overheating, compromised Z06. So be careful what you ask for, you may get it!
------------------------------------------- 8/20/2018 Update ------------------------------------------------------------------------
Now that I have data on the C7 ZR1 I thought I would update this post. A C7 ZR1 is the heaviest Corvette ever. With M7 and Track Performance Package (ZTK – High Wing) and no fuel it is 3501 pounds, with full fuel 3615, with 3ZR (Heated seats, PDR, Premium audio, etc.) 3647 pounds. The good news is that at Summit Point Motorsports Park it did not overheat and it recorded consistent lap times on a 30 minute run. https://www.corvetteforum.com/forums...ay-report.html The bad news is that it got only 2.9mpg on 93 octane and most of the time the driver was not any faster than when he drove a C7 Z06 at this track.
As an interesting aside, NASCAR Cup cars with 5.8 Liter engines producing 850 horsepower get 4.5mpg at Watkins Glen. Supercharging may be great at the dragstrip but for road racing it is very inefficient from parasitic HP loss and heat generated that requires additional coolers which adds drag and weight.
Last edited by grcor; 08-20-2018 at 08:48 PM. Reason: C7 ZR1 update
07-26-2016, 07:51 PM
#2
Drifting
Interesting points made, I do like the new Z but will stick with my 09 Cyber/Grey Z.
It is a heads/cam/headers car but I get better mileage than stated. 24 normal , 30 steady highway. I also do HPDE's and track mileage is around 11 or 12 so I guess I am far from "expert". Ha.
It is a heads/cam/headers car but I get better mileage than stated. 24 normal , 30 steady highway. I also do HPDE's and track mileage is around 11 or 12 so I guess I am far from "expert". Ha.
07-27-2016, 11:28 AM
#5
Safety Car
Thread seemed bias from the start, in my opinion.
This is yet another "OMG the C7 Z06 overheats.. long live the C6!" thread. How many people with C6 Z06s actually participate in HPDEs? Almost 0%.
Your thread title makes it sound like this is about gas mileage, but all you talk about is racing. Which is a better track car? The cheaper of the two, because _both_ will need tweaks to get the last ounce of performance out of them. You could make the same argument on the C5Z versus the C7Z.
Unless you're racing competitively, the cost of fuel and the amount consumed are of little relevance. These cars are driven primarily on the street, not on race tracks.
This is yet another "OMG the C7 Z06 overheats.. long live the C6!" thread. How many people with C6 Z06s actually participate in HPDEs? Almost 0%.
Your thread title makes it sound like this is about gas mileage, but all you talk about is racing. Which is a better track car? The cheaper of the two, because _both_ will need tweaks to get the last ounce of performance out of them. You could make the same argument on the C5Z versus the C7Z.
Unless you're racing competitively, the cost of fuel and the amount consumed are of little relevance. These cars are driven primarily on the street, not on race tracks.
Last edited by Tech; 07-27-2016 at 11:34 PM.
07-27-2016, 11:44 AM
#6
Banned Scam/Spammer
If you buy a vette and worry about gas mileage or gas during your racing you bought the wrong car. If gas mileage is important to you, buy a prius.
I usually get 7mpg in the city, and I love every moment of it. I drive it like I love it.
I usually get 7mpg in the city, and I love every moment of it. I drive it like I love it.
The following 2 users liked this post by yellowzron:
RobGOV-DCZ (08-03-2016),
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07-27-2016, 02:38 PM
#7
for tires. I paid $550 for my last rear set and they last 6k miles. hoosier drag radials
07-27-2016, 06:16 PM
#9
Food for thought A "session" is 27 miles. At 6 mpg, the C6Z would burn 4.5 gallons of gas. The C7Z would burn 7.71 gallons. I'm not sure what blend of gasoline you are running BUT... one gallon of regular gas contains 125,000 BTU's Not counting friction, just the heat from combustion, the C6Z would generate 562,500 BTU's on the run and the C7Z would generate 963,750 BTU's. No wonder the C7's are struggling with keeping cool on the track.
07-27-2016, 11:50 PM
#10
Melting Slicks
Pro Mechanic
Member Since: Nov 2013
Location: Ex DPRK, now just N of Medford, OR
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I am concerned with my fuel mileage. But in overall context it's ludicrous to consider that as a major factor for a track day...
"OH SH*T! I burned $40 worth of gas that session, instead of the $20 that I normally burn in my C5!". Silly.
1000 mile trip on the hiway, yeah. C5 does 28, C6Z... ahh, not so much. Don't care about the C7, not buying one regardless.
"OH SH*T! I burned $40 worth of gas that session, instead of the $20 that I normally burn in my C5!". Silly.
1000 mile trip on the hiway, yeah. C5 does 28, C6Z... ahh, not so much. Don't care about the C7, not buying one regardless.
07-28-2016, 08:30 PM
#11
I am concerned with my fuel mileage. But in overall context it's ludicrous to consider that as a major factor for a track day...
"OH SH*T! I burned $40 worth of gas that session, instead of the $20 that I normally burn in my C5!". Silly.
1000 mile trip on the hiway, yeah. C5 does 28, C6Z... ahh, not so much. Don't care about the C7, not buying one regardless.
"OH SH*T! I burned $40 worth of gas that session, instead of the $20 that I normally burn in my C5!". Silly.
1000 mile trip on the hiway, yeah. C5 does 28, C6Z... ahh, not so much. Don't care about the C7, not buying one regardless.
Are you referring to my post as "ludicrous"? I'm only posting numbers.
Does the C7Z have twice the cooling capacity of the C6Z? My post has nothing to do with $ cost, only heat. The stock C7Z is known for it's inability to deal with heat on the track. My numbers give a good reason why. I'm up for argument.
07-28-2016, 09:56 PM
#12
I love to blow peoples minds when I tell them my Z06 get 27 mpg on the highway. I have no clue what i get in town, I would guess about 12-14mpg. The little needle gets to 1/4 tank I fill it up. My Dodge truck gets 11mpg no matter where or how I drive it. My previous 03 Cobra got 8 in town an maybe 11mpg on the highway. My Corvette is a fuel miser.
07-29-2016, 10:41 AM
#13
But I don't know much about racing so I could be completely off track. Just a thought.
07-29-2016, 11:18 AM
#14
Melting Slicks
Pro Mechanic
Member Since: Nov 2013
Location: Ex DPRK, now just N of Medford, OR
Posts: 2,917
Received 736 Likes
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Are you referring to my post as "ludicrous"? I'm only posting numbers.
Does the C7Z have twice the cooling capacity of the C6Z? My post has nothing to do with $ cost, only heat. The stock C7Z is known for it's inability to deal with heat on the track. My numbers give a good reason why. I'm up for argument.
Does the C7Z have twice the cooling capacity of the C6Z? My post has nothing to do with $ cost, only heat. The stock C7Z is known for it's inability to deal with heat on the track. My numbers give a good reason why. I'm up for argument.
07-29-2016, 12:10 PM
#15
Team Owner
I have a 2009 Z06. As for gas mileage, I average 29 on long distance road trips(not the window sticker of 24 MPG), and have cruised at 35 MPG at 74 MPH under perfect conditions. I have had a best gas mileage of 33.0 MPG average for 450 miles between Springfield, MO and Natchez, MS. Normal driving, in the mountains, two lane roads, small towns with traffic lights, Interstates, etc and still see 33.0 MPG average for 450 miles.
That's is way better than the C7 Z06. On a 3,400 mile road trip. I averaged 29.2 MPG and a C7 Z06 averaged 24.0 MPG on the same road trip.
I also average $275 annually for tires on my Z06. Bridgestone RE050A run flats that will get 40,000 miles of life.
Fuel consumption on the track is of no concern. It's a minor expense compared to all the other expenses of tracking your car. I get around 4 MPG instantaneous when running WOT at over 160 MPH on the track. I gets better when I let off the gas in the corners.
That's is way better than the C7 Z06. On a 3,400 mile road trip. I averaged 29.2 MPG and a C7 Z06 averaged 24.0 MPG on the same road trip.
I also average $275 annually for tires on my Z06. Bridgestone RE050A run flats that will get 40,000 miles of life.
Fuel consumption on the track is of no concern. It's a minor expense compared to all the other expenses of tracking your car. I get around 4 MPG instantaneous when running WOT at over 160 MPH on the track. I gets better when I let off the gas in the corners.
Last edited by JoesC5; 07-29-2016 at 12:13 PM.
07-29-2016, 02:49 PM
#16
I'm all about efficiency and the efficiency of the c6 z06 of turning gas into power was a big selling point for me. I simply wouldn't have bought it if it got ferrari-like mpg numbers. That's just too much waste for me.
07-30-2016, 12:41 AM
#17
From the get-go, your first point about gas milage getting better with each generation is wrong. The C5 (non-Z06) gets the best MPG. I'm not sure where you are coming from here. More power, more fuel, more heat, more cost, more fun. Just buy the damn car and quit making excuses 
.
.
07-30-2016, 06:49 PM
#18
Le Mans Master
My not too extreme LS3 gets some pretty crappy mpg. On E85 I get 12. On E10 (superunleaded) I get about 15. That's driving it a bit hard.
On the few highway trips I've taken low 20s. I'd actually like some decent mpg like the C7s get.
So yes, it matters to me.
On the few highway trips I've taken low 20s. I'd actually like some decent mpg like the C7s get.
So yes, it matters to me.
08-03-2016, 02:40 PM
#19
Thread seemed bias from the start, in my opinion.
This is yet another "OMG the C7 Z06 overheats.. long live the C6!" thread. How many people with C6 Z06s actually participate in HPDEs? Almost 0%.
Your thread title makes it sound like this is about gas mileage, but all you talk about is racing.
This is yet another "OMG the C7 Z06 overheats.. long live the C6!" thread. How many people with C6 Z06s actually participate in HPDEs? Almost 0%.
Your thread title makes it sound like this is about gas mileage, but all you talk about is racing.
My second paragraph is about street mileage. Maybe you should reread my post.
08-07-2016, 02:05 PM
#20
Team Owner
I would like to look at this question from the standpoint of street driving and track driving.
For the street the C6 Z06 gets 15 mpg city and 24 mpg highway. The C7 Z06 automatic gets 13/21(2014-2015) 13/23 mpg (2016) and the manual gets 15/22 mpg. https://www.fueleconomy.gov/feg/printGuides.shtml Most of the time each new car generation gets better mileage than the previous, but not the C7 Z06. The reason why has to do with changes people asked for like upgraded interior, better seats, open air experience, etc. The engineers needed to meet new safety regulations and add performance features like the electronic deferential and rev matching downshift, etc. But all this stuff adds weight and to overcome this weight they decided to go to a supercharged engine, which adds even more weight and the parasitic loss from supercharging hurts gas mileage. To improve mileage they added variable valve timing, more transmission speeds, and cylinder deactivation which added a lot more parts and reengineering existing parts which in turn adds weight. So the engineers got themselves into a vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight and so the C7 Z06 is 300 to 350 pounds more than the C6 Z06 at a time when other GM cars are losing that much weight.
Now how does gas mileage effect track driving from the standpoint of cost, heat, and the driving experience. Let’s take a look at what it costs to run a Z06 for a day at the track. In the hands of an expert driver the C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg. Let’s assume that you fill up just before you get to the track; you have half a tank, so you put in 9 gallons to give you a full tank. For those of you who get 5 sessions at 20 minutes (27 miles) per session; C6 Z06 would use 4.5 gallons per session, you fill up after 3 sessions (13.5 gallons), you run session 4 and 5 which leaves you 9 gallons in your tank to get home. C7 Z06 would use 7.7 gallons per session, you fill up after session 2 (15.4 gallons), you fill up after session 4 (15.4 gallons), you run session 5 which leaves you 10.3 in your tank to get home. For the C7 Z06 I am going to make the assumption that you’re very lucky that it does not overheat during any of the sessions because you did the track preparation in the owner’s manual and it is a very cool day. I am going to use California gas prices; $3.00 outside the track, $6.00 at the track. For the C6 Z06 total gas cost is $108.00 (9 * $3.00 + 13.5 * $6.00) for a day at the track. For the C7 Z06 total gas cost is $211.80 (9 * $3.00 + 15.4 * $6.00 + 15.4 * $6.00) for a day at the track. It costs the C7 Z06 owner almost 2X more for a day at the track if the car can run the whole time.
Now let’s look at gas mileage from the standpoint of heat generated. The C7 Z06 is using 71% more gas than the C6 Z06 (C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg). I am not sure if I can say that translates directly into 71% more heat the cooling system has to dissipate, but I think we all can agree it is substantially more heat that the cooling system has to dissipate. Now it should be painfully obvious why the C7 Z06 has such an overheating problem. On top of that the C7 Z06 has the intercooler radiator setting in front of the engine radiator. Not only does the intercooler radiator slightly restrict airflow to the engine radiator but it is heating up the air before the engine radiator gets it. After market Radiator manufactures have tried higher capacity radiators with little to no effect because of the issues I have mentioned above with the intercooler radiator and the large belly pan further restricting airflow. The only way a higher capacity radiator can work is if there is a sufficient flow of cool air. LG and GSpeed are putting additional openings in the front of the car with separate air inlets for each radiator/cooler. I think they will eventually be successful in solving the cooling problem, but unfortunately they will have created 3 new problems. The new air inlets will create substantially more drag and lift and the additional radiators/coolers with add weight in front of the front tires skewing the balance of the car. The Chevrolet engineers are no dummies and I am sure they have already looked at this approach and discarded it because of all the new problems that it creates. So what you will see from Chevrolet are more band aids like the rear mounded cooler, power steering scoop, and larger hood openings in the 2017 Z06. None of which totally solve the problem. This is another example of the vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight>Cooling solutions>Weight has done to the C7 Z06.
You could take a C5 Z06 and C6 Z06 right from the show room to the track and run HPDE sessions all day with no problems. Unfortunately that is not the case with the C7 Z06 even though it is sold as a track car. Turning one fast lap is meaningless when each additional lap is slower and then you overheat. A person cannot test/gauge/improve their driving ability with a car that does not provide consistent performance. This is why the C5 Z06 and C6 Z06 are truly great track cars.
So to make the C7 appeal to as many people as possible particularly those asking to be “comfortable” and have an “open air experience” we ended up with a dumbed down, over weight, overheating, compromised Z06. So be careful what you ask for, you may get it!
For the street the C6 Z06 gets 15 mpg city and 24 mpg highway. The C7 Z06 automatic gets 13/21(2014-2015) 13/23 mpg (2016) and the manual gets 15/22 mpg. https://www.fueleconomy.gov/feg/printGuides.shtml Most of the time each new car generation gets better mileage than the previous, but not the C7 Z06. The reason why has to do with changes people asked for like upgraded interior, better seats, open air experience, etc. The engineers needed to meet new safety regulations and add performance features like the electronic deferential and rev matching downshift, etc. But all this stuff adds weight and to overcome this weight they decided to go to a supercharged engine, which adds even more weight and the parasitic loss from supercharging hurts gas mileage. To improve mileage they added variable valve timing, more transmission speeds, and cylinder deactivation which added a lot more parts and reengineering existing parts which in turn adds weight. So the engineers got themselves into a vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight and so the C7 Z06 is 300 to 350 pounds more than the C6 Z06 at a time when other GM cars are losing that much weight.
Now how does gas mileage effect track driving from the standpoint of cost, heat, and the driving experience. Let’s take a look at what it costs to run a Z06 for a day at the track. In the hands of an expert driver the C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg. Let’s assume that you fill up just before you get to the track; you have half a tank, so you put in 9 gallons to give you a full tank. For those of you who get 5 sessions at 20 minutes (27 miles) per session; C6 Z06 would use 4.5 gallons per session, you fill up after 3 sessions (13.5 gallons), you run session 4 and 5 which leaves you 9 gallons in your tank to get home. C7 Z06 would use 7.7 gallons per session, you fill up after session 2 (15.4 gallons), you fill up after session 4 (15.4 gallons), you run session 5 which leaves you 10.3 in your tank to get home. For the C7 Z06 I am going to make the assumption that you’re very lucky that it does not overheat during any of the sessions because you did the track preparation in the owner’s manual and it is a very cool day. I am going to use California gas prices; $3.00 outside the track, $6.00 at the track. For the C6 Z06 total gas cost is $108.00 (9 * $3.00 + 13.5 * $6.00) for a day at the track. For the C7 Z06 total gas cost is $211.80 (9 * $3.00 + 15.4 * $6.00 + 15.4 * $6.00) for a day at the track. It costs the C7 Z06 owner almost 2X more for a day at the track if the car can run the whole time.
Now let’s look at gas mileage from the standpoint of heat generated. The C7 Z06 is using 71% more gas than the C6 Z06 (C6 Z06 gets 6 mpg and the C7 Z06 gets 3.5 mpg). I am not sure if I can say that translates directly into 71% more heat the cooling system has to dissipate, but I think we all can agree it is substantially more heat that the cooling system has to dissipate. Now it should be painfully obvious why the C7 Z06 has such an overheating problem. On top of that the C7 Z06 has the intercooler radiator setting in front of the engine radiator. Not only does the intercooler radiator slightly restrict airflow to the engine radiator but it is heating up the air before the engine radiator gets it. After market Radiator manufactures have tried higher capacity radiators with little to no effect because of the issues I have mentioned above with the intercooler radiator and the large belly pan further restricting airflow. The only way a higher capacity radiator can work is if there is a sufficient flow of cool air. LG and GSpeed are putting additional openings in the front of the car with separate air inlets for each radiator/cooler. I think they will eventually be successful in solving the cooling problem, but unfortunately they will have created 3 new problems. The new air inlets will create substantially more drag and lift and the additional radiators/coolers with add weight in front of the front tires skewing the balance of the car. The Chevrolet engineers are no dummies and I am sure they have already looked at this approach and discarded it because of all the new problems that it creates. So what you will see from Chevrolet are more band aids like the rear mounded cooler, power steering scoop, and larger hood openings in the 2017 Z06. None of which totally solve the problem. This is another example of the vicious circle of adding Comfort features>Weight>Performance features>Weight>Supercharging>Weight>Gas mileage enhancements>Weight>Cooling solutions>Weight has done to the C7 Z06.
You could take a C5 Z06 and C6 Z06 right from the show room to the track and run HPDE sessions all day with no problems. Unfortunately that is not the case with the C7 Z06 even though it is sold as a track car. Turning one fast lap is meaningless when each additional lap is slower and then you overheat. A person cannot test/gauge/improve their driving ability with a car that does not provide consistent performance. This is why the C5 Z06 and C6 Z06 are truly great track cars.
So to make the C7 appeal to as many people as possible particularly those asking to be “comfortable” and have an “open air experience” we ended up with a dumbed down, over weight, overheating, compromised Z06. So be careful what you ask for, you may get it!
The much improved stiffer handling.
The lt4 is the most powerful and best engine yet from GM.
C7>C6 >C5 natural progression.
Then you bring up the C5? Gotta be the C5Z06 or don't bother bringing
it up. Had one of those too. Great car in the day. C6Z06 Great car in the day. The C7 Z06 much better car than either and a new era!
Not sure what you are rambling about. Mine shows 28.9 as my best and the car has over 20,000 miles and makes an average all around of
a little over 20 city/hiway over the life of the car.
As far as a driver the new car is miles ahead of the previous car.
I still drive my 2008 and it is crude compared the 2015.
Sounds like your trying to dumb down yourself into thinking the old car compares. Not really the new Car has moved the Corvette in to a different league.
You haven't the FOGGIEST idea of what your posting.
Last edited by 3 Z06ZR1; 08-07-2016 at 02:07 PM.