I'm new to my S4 and I don't think I'll even get 300kms for this full tank or the next few till I start driving normal and less spirited driving.

 

i have found that the rs4 is excellent on the highway at"calm" speeds (110 or so).

as i mentioned abode i never really drive highway in it (the b8 a4 Avant 2.0t is the car that gets tasked with the long drives)

on a trip to muskoka i took the rs4 with wife and dog and about 50 lbs of luggage. filled up at the beginning

here is the readout on the trip odometer and the dis....both of which were reset right at the start of the trip. interestingly the dis was pretty close to the trip odo.

80% highway + some 20% 'city' driving around a couple of towns at my destination. on the highway, I locked the cruise in at 110 km/h which is 70 MPH. I was conscious about it and made sure to just take it easy. May as well as it was a long weekend and there were speed taps everywhere. Here are the numbers, calculated and DIS to get an idea how accurate the RS4 DIS is.

fuel used 58.01 litres a.k.a. 15.3 gallons (that's what the tank took after I pulled off the highway to fill up on the way back home. There was likely about 20 miles or 30 kms that I could have travelled as there should have been another gallon or near four litres in the tank.

miles travelled 345.2/555 kms
calculated MPG = 22.50/10.4 l/ 100km
DIS indicated MPG = 22.7 (pretty accurate surprisingly...my b7 S4 DIS was off 10%)

on the highway-only portions of the trip, dis indicated 25-26 mpg, and i have replicated that quite a few times since over the course of door to door highway mostly trips.