I was told by two mercedes mechanics ( both race e55 and e63 both mix e85 they use 35% because both have bigger injectors they said only if you go e85 only do you need the o-ring changed on the bigger injectores and remove the fuel filter/regulator and add a manual fuel regulator hoses are ok.. he is talking about Mercedes not the crossfire ???did they use the same hoses on mercedes and crossfire ?? in a few months we will know how it works ,,track time and pump and hose inspections, jim