An Engineer for one of the 'Big Three' welding equipment manufacturers told me awhile back that friction plays a part durring the gas delivery through the hose. Longer the hose - more of a loss in c.f.h. readings at the nozzle. Now, whether you believe that or not...it has some merit. We run about 100 ft. of gas hose off our rigs and the regulators need to be set at around 50 c.f.h. to get 25 at the nozzle. Different story in the shops, with much shorter gas hoses (10ft). There it's about tit for tat. So in my case, even if it was bs it still corrected a problem.