Been collecting the upgrade list for the vehicle and stumbled upon a "hood vent kit". That one is most likely cosmetic (while the one I used to have on the Jeep was quite functional), but it got me thinking - what are the things that you folks did to your Defenders that made them feel cooler, and were there things that backfired?

One of the things that I'm concerned with is - will underbody protection cause overheating above a safe threshold?

Just one point of reference, local ground temperature in the summer can easily reach 160F on an average day. Blacktop is even hotter.

 

OEM setup has felt underneath with oodles of air between it and the transmission/diffs/engine etc. Same air insulator will be there with underarmor.

These temps, while a balmy 160F, pale in comparison to heat generated by the ICE.

I think the temperature of the incoming air will have orders of magnitude more heat energy imparted to the engine than radiant heat from the ground and material under the car. The metal under there never gets hotter than ambient.

A bit like using a hair dryer duct taped to the intakes versus strapping a few gently warm hunks of metal to the car.

I think there would be zero heat impact of any relevance related to under armor.

 

I was more concerned about the extra heat trapped by the armor than radiation from the ground - that temperature was just for the reference, I'm sure (based on past telemetry logs from other vehicles) the vehicle will behave differently than, say, at Midwestern summer temperature. From what you're saying it sounds like trapping the heat won't be a concern, then?

 

The loss of heat from engine, transmission, diffs to the ambient air beneath them compared to the engine and transmissions cooling system would be negligible.

the delta T would be reduced but it’s such a minor factor compared to the orders of magnitude more heat lost to the cooling systems it’s almost a kim factor.

longterm of course, harsher temperatures will have an impact. How much, that’s an unknown.

perhaps any cumulative effects would be easily mitigated by more frequent engine and transmission fluid change.

interesting idea but I am skeptical. It’s not passing the smell test. .