Several years ago I installed a Poison Spyder vent on a previous TJ. I saw no difference in the engine operating temperature. What I did see was:
- the elimination of the hot start stumble that happened every Summer, when shutting of the engine and restarting it while hot (e.g. getting gas)
- a reduction in the hood temperature, i.e. the front of the hood would be so hot I'd have to open it with gloves.
The single biggest benefit was I no longer had to pop open my hood, to let the engine bay cool, every time we stopped for a quick break on the trail
- the elimination of the hot start stumble that happened every Summer, when shutting of the engine and restarting it while hot (e.g. getting gas)
- a reduction in the hood temperature, i.e. the front of the hood would be so hot I'd have to open it with gloves.
The single biggest benefit was I no longer had to pop open my hood, to let the engine bay cool, every time we stopped for a quick break on the trail