What is the benefit of having a fuel return hooked up for a Weber 48 IDA? Is it ok to run without one? What are the performance gain/loss?

 

Having the return reduces vapor lock (air bubbles in the fuel lines) in hot weather. It also reduces some stress on the fuel pump keeping it a little cooler which may extend pump life....its usually a little quieter too!

No loss or gain....its preference pretty much. I don't run a return and have never had a problem on the IDA.

...however a Holley Red at LACR years ago fueling a Holley vapor locked and I had a hellova time gettting home....had to keep stopping, remove the line, and try to re-pressurize the system, either turn on the pump and wait for fuel to come out, or suck until the bubble came out! This is why I like the "gearotor" setup the Mallory has vs. the rotor/vane of the Holley.