Hi,
I'm a company car driver and have an SQ5, if you keep it in 'D' around the 60 to 70MPH mark you'll get great mileage. I've had 40MPG (according to the computer).
Obviously, if you drive it quick and use the paddles and 'S' you will get nearer 34MPG.
All in all I'm over the moon with everything about my SQ5.
What to take in to account also is it defies gravity!! Genuinely quick!
You'll love it!
Burnsy