What is better; HOH (hose on hose) or HIH (hose in hose)?
Hose in hose has been standard for years. As your fuel is pumped to the engine it is piped through a line that is inside your coolant line, and therefore heated by coolant that surrounds it. The only problem with that is if there is a leak in the fuel line there is the danger that your fuel and coolant will mix and you wont know it until its too late. If there is a breach in the coolant line, the whole bundle must be redone. HOH is 2 coolant hoses on top of or bundled to the fuel line to share heat. It works just fine, and there is no danger of contaminating your fuel or coolant.
