I’ve had a T4 XC40 for about 9 months now. For the first 4-5,000 miles the car refused to exceed 30MPG on a combined cycle which is far short of the advertised figure. In reality it was more like 28MPG.
I’m now sat on around 9,000 miles and the car is comfortably sitting at an average of 34.2MPG for the last 600 miles. In a recent 420 mile motorway trip, it returned 38.1MPG.
The general concenous is that the fuel economy improves after the first 5,000 miles of break-in, but its certainly not brilliant. I would say however that its an excellent engine – very smooth, quiet and a nice linear power delivery with plenty of punch.
For reference, mine is the 4WD model so would expect the FWD T4 to be very slightly better on fuel economy.