Little confusing... LEDs typically use less power than a headlight. Without a doubt. I'm saying that having any form of DRL is going to cause a vehicle to consume more fuel (SFA more... but, more nonetheless)
DRLs have been around for many many years. One of my daily runners in the US was a 96 Toyota Tacoma (Hilux) as it was a northern states vehicles it was released from the factory with a DRL module. Once the vehicle went into drive my headlights would automatically come on and stay on until I switched the car off. BUT if the bulbs were on 100% of 100% of it's operating life then I would be buying new bulbs every 12 months and have a constant 110W draw from the alternator regardless (hence more fuel). So instead, the module used to drop the voltage to the bulbs down to about 8volts. Brighter than park lights and extended bulb life, lower output from the alternator and still highly visible on the roads. Now in the past few years we have seen the swap to DRLs being LED it means that bulb life doesn't factor into the equation and at about 20watts consumption the alternator doesn't really care either.
The average Australian really only knows DRLs as being LEDs. Reality is, the rest of the world knows different