Where is my fuel cooler?!?

[BRRV]

So, perhaps there's another reason for using only quality gasoline, although I have to admit that, here in Denver, all the gas comes off the same rail at the same refinery and it's the additives package that gets adjusted. Anyway, seems to me that this would be a good reason to add some form of outer insulation to the rubber fuel lines leading to and from the gas tank, in the engine compartment. That couldn't hurt and would be simple to do. However, In my personal experience, vapor locking is due more to the loss of fuel system pressure due to a under-performing in-tank or overworked main fuel pump (with a failing internal check valve?). I know some folks discount this, but it's the first thing listed in the Bosch fuel injection diagnosis manuals I have. The only time I've EVER experienced this issue is with fuel system pressure problems. ShawnD nailed it.

[Shawn D.]

Okay Mike, so maybe we have now identified the true purpose of this device. Its little to do with cooling fuel prior to its use, rather its to stop excessive fuel vapour in the tank being expelled via the breather system, back to the engine intake.

That's a secondary purpose. If you get vapor lock, the fuel pump(s) performance will suffer severely and the vehicle will stop running -- that's the main issue.