Fuel capacity from accessing the digital info:

Start 46.0 Liters, End 25.2 Liters, Fuel Burned 20.8 Liters

Mileage 126.3, All around town, no highway, occasional hard (fun ) driving, but usually shifting at 3.5 to 4K.

20.8 Liters = 5.5 Gallons (US)

Works out to 22.9636 mpg, call it 23 mpg

Mini Cooper S, 2002, No mods, 16" Pirelli Runflats, Aero Package, 4500 Miles

How does that compare to what you're seeing?

 

Just made a trip up north, expressway (75-80 mph), city and country driving. 407 miles, 11.0 gal., 37 mpg

 

my Fuel Economy, from day one. Driving ranging from pedal-to-the-metal Deal's Gap to cruise control on the interstate.

Total Miles: 3641
Total Gallons: 129.9
Overall MPG: 28.0

 

I am averaging about 28 to 29 MPG in my MCS. 60 to 80% freeway driving.

 

>>Works out to 22.9636 mpg, call it 23 mpg
>>
>>Mini Cooper S, 2002, No mods, 16" Pirelli Runflats, Aero Package, 4500 Miles
>>
>>How does that compare to what you're seeing?

I've also got an MCS, 16" Dunlops, no Aero package, 4900 miles. I'm getting about the same MPG as you.

 

in my '03 MC, I get anywhere from 29 MPG (drivin fast in the twisties) to 35 (highway cruising, AC on). most fill up average about 33.

I can and have gone 400 miles on 1 tank of fuel!

 

You might check tire pressure. I only use premium 92 octane gasoline.
2003 MCS with 3200 miles. I get up to 35 mpg on the highway and usually 28 in mixed driving. If I really drive hard I usually average about 25. On the track I get about 21 or 22 mpg. I have a madness intake, S-lite wheels and run flat Pirelli tires.

 

02/02 build MINI Cooper 5-speed:

 

OK, so now I ran a highway test:

State College, PA to Altoona, PA, I-99, some back roads, 90% highway, finally saw 100mph

Start 46.0 Liters, finish 37.9 Liters, 85.3 Miles

Consumption = 8.1 Liters = 2.14 gallons (US)

Works out to 39.8598 mpg !!! WOW !!!

BTW, constant vigilance required to keep her under 90mph on the highway...I'm gonna need a radar detector!