I've been seriously considering running WVO in my 2000 PSD. During my long, sleepless nights thinking about it, it occurred to me that by using the coolant to heat the WVO that your adding at least 20' to your heater hose, and a couple gallons of coolant. What type of additional stress does this put your water pump under?

There is, what, 20' of hose in your entire coolant system? Now you're doubling it, and it is all small diameter hose running very long lengths...

How drastic is the temperature change on the coolant when it returns to the original line? There is a lot of heat getting sucked into the WVO I'd imagine it is significant up to a certain degree... does that also play a role on the remainder of your coolant system?