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GM addressed adding insulation to the trunk. The reality is all insulation does is slow down heat transfer. So for shorter trips, yeah, it would stay cooler. But after enough time (depending on the R value) you'd reach the same temps anyway. Insulation won't make it cooler, it will make it warm up slower. Depending on how you insulate, you may get the added effect of keeping it warmer longer too. Think of how outdoor ovens work. They take a while to get hot, but once they do, they stay hot.
True if just thermal insulation that slows heat transfer. A heat reflective material combined with insulation can limit the heat if there is a path to emit heat out of another trunk surface. There are other paths for the heat to travel than just to the trunk. Otherwise my trunk would get as hot as the engine, and engine compartment, and doesn’t.
Did a 340 mile drive yesterday and recorded a high of 130 degrees in the trunk. Approximately 45 minutes after arriving home it was showing 126 degrees. Ambient outdoor temperature was around 90.
We never use the rear trunk, too hot. Frunk is very handy.
There are times where the heat is helpful - BUT!
SIDEBAR
Wife and I left a restaurant and had a doggy bag with a plastic clamshell holding a hot leftover meal. Thought Truck will be fine with its flat floor (have a tool bag in the Frunk.) Got home and bag had slide sideways into the "hole on one side!" Contents had spilled but some was caught in the bag AND I have the GM Jake Rubber truck mat! Clean-up was easy. BUT decided I needed what I had in my two C7's when carrying things like a milk carton. Bought a carrier that measurements showed would fit BUT the odd shapes of the trunk had it too high in the rear, which is tapered. Fortunately, was from Amazon so sent it back!
This is what I built, modified from my C7:
Used in C7s. Fits in Ballistic Nylon carrier
Folds flat when not in use, as does Nylon carrier
Modified for C8. Note Trunk rear is tapered so had to trim. Purchased narrow Nylon carrier but was too high in rear and was returned.
When not in use, parts disassemble in seconds and fit flat in net. BTW, that folded fender cover is what I use when lifting heavy stuff over the rear Z51 wing. Helps with bulky things like golf bags. It has a high friction bottom that holds on wing. Inexpensive.
If interested this is from a PDF I also have but all you need to understand the build
Did a 340 mile drive yesterday and recorded a high of 130 degrees in the trunk. Approximately 45 minutes after arriving home it was showing 126 degrees. Ambient outdoor temperature was around 90.
Without comparison data, this doesn't really tell us much. How hot would the trunk of a similar color front engine car be after 340 miles in the not sun?
