Engine Cooling
Pro
Joined: Oct 2019
Posts: 739
Likes: 640
From: San Jose CA
Its your car. scoop away.
Burning Brakes
Joined: Feb 2009
Posts: 844
Likes: 381
To answer one of the original questions raised on my Z06 I added the factory aluminum scoops underneath the car that come on the European Z06’s, and on my ZR1 I added the underneath scoops (aftermarket units) that are slightly taller for a bit more air flow given the greater heat generation.
Drifting
Joined: Jun 2021
Posts: 1,292
Likes: 749
From: Phoenix, Arizona
To answer one of the original questions raised on my Z06 I added the factory aluminum scoops underneath the car that come on the European Z06’s, and on my ZR1 I added the underneath scoops (aftermarket units) that are slightly taller for a bit more air flow given the greater heat generation.
1st Gear
Joined: Apr 2026
Posts: 1
Likes: 0
I find it interesting, and annoying, that my 2026 (delivered Feb 20th 
) C8 HTC SR has such a high temp. thermostat. Yes, I read that keeping it near 200 is better for efficiency, understood.
What I am very interested in, is adding the capability to run cooler as I approach home or any other destination (like a fan switch). AND, the capability to cool it off when I stop. I'm awaiting having a garage built, and don't want to wait an hour to install the car-cover for fear that it will melt.
Sidenotes: I did buy some heat shielding to put under the trunk's carpeting. Also, I plan to buy a set of air scoops that force air up from the bottom.
) C8 HTC SR has such a high temp. thermostat. Yes, I read that keeping it near 200 is better for efficiency, understood.What I am very interested in, is adding the capability to run cooler as I approach home or any other destination (like a fan switch). AND, the capability to cool it off when I stop. I'm awaiting having a garage built, and don't want to wait an hour to install the car-cover for fear that it will melt.
Sidenotes: I did buy some heat shielding to put under the trunk's carpeting. Also, I plan to buy a set of air scoops that force air up from the bottom.
Drifting
Joined: May 2005
Posts: 1,560
Likes: 334
From: Indianapolis Indiana
I have to tell a funny here. I have a Motor Trend nylon car cover. It's like a parachute. The only time I covered my C8 when it was hot the heat rising created a balloon effect. It settled down quickly but I showed it to my wife and the perplexed look on her face was hilarious.
Race Director
Joined: Mar 2007
Posts: 11,229
Likes: 8,372
The service manual appears to say its 190 degree. There is a thermostat diagnostic procedure that indicates (using tempil sticks) that the thermostat should start to open at 188 deg F and be fully open at 206 deg F"
"The 188 tempil stick melts at 87°C (188°F). The thermostat should begin to open.
The 206 tempil stick melts at 97°C (206°F). The thermostat should be fully open."
Also if you have Z51 there is going to be a second thermostat. One is "Engine Coolant Thermostat Replacement - At Engine Coolant Manifold". They all have this one.
The second one is "Auxiliary Radiator Inlet Hose to Auxiliary Radiator Inlet Hose" - if you have Z51. As far as I can tell they are the same temperature stats.
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Melting Slicks
Joined: Jun 2004
Posts: 3,492
Likes: 696
From: panama city beach florida USA
St. Jude Donor '09
Thread Starter
Intermediate
Joined: Nov 2025
Posts: 30
Likes: 7
From: Dayton, OH
Thread Starter
Intermediate
Joined: Nov 2025
Posts: 30
Likes: 7
From: Dayton, OH
Interesting. My non-Z runs so much cooler than any temps reported in this thread. In cooler weather mine seldom gets above 167°. When it gets hot out (Western Washington highs in 90s) it goes clear up to 173°. I can run it down the freeway in 4th gear for the better part of an hour and it won't hit 175°. The only way I can get the temp up hot enough to check the oil is to sit and idle for a few minutes.
hmmm.
hmmm.
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,180
From: Central Illinois
This may be a typical American mind set that cooler is better, it's not. After 4 years my 2020 SR (non Z51) never saw 190 degrees. Overcooling fluids can cause more harm than good. 200 degree oil is fine, some cars (VWs) typically have oil temps (not coolant) of 220-225 degrees and that's not in traffic, just rolling down the interstate with all the air flow it will ever see. My Z06 runs too cool for my taste, and the harder it's driven, it seems to not matter to it.
Burning Brakes
Joined: May 2023
Posts: 1,000
Likes: 355
From: Ontario
This makes me wonder cool down time of the HTC vs coupe. And, I know the top is supposed to be put up when parked but I’m guessing the engine compartment stays hotter longer if left down or in traffic. I don’t cover my car often after driving due to dirt and possible scratches but if I do, I’ll wait for it to cool.
Burning Brakes
Joined: May 2023
Posts: 1,000
Likes: 355
From: Ontario
This may be a typical American mind set that cooler is better, it's not. After 4 years my 2020 SR (non Z51) never saw 190 degrees. Overcooling fluids can cause more harm than good. 200 degree oil is fine, some cars (VWs) typically have oil temps (not coolant) of 220-225 degrees and that's not in traffic, just rolling down the interstate with all the air flow it will ever see. My Z06 runs too cool for my taste, and the harder it's driven, it seems to not matter to it.
Racer
Joined: Apr 2021
Posts: 459
Likes: 397
From: Mason, OH
When I had my '21 Z51 Coupe water temps seemed to always be in the 180-185 range, regardless of how hard driven even when it was almost 100 outside temp. When I traded that in for a '24 non-Z51 HTC I was somewhat initially concerned when it typically ran 190 - 200, sometimes getting up to 205. What cured me of even thinking about water temps again was one winter I had to take it on a long highway road trip through the mountains when it was 4 degrees outside and the car still ran in the 195-205 range. Figured if it was consistent despite an almost 100 degree outside temperature swing then it must be working as intended.
