[MusicLoverUK]

I find that my Passat GTE estate does typically 45mpg when running on petrol, and obviously uses no petrol when on electric, so my overall MPG just depends on what percentage of my mileage I do on electric. Over the last year I've achieved nearly 100mpg because I've been about 50% electric. My petrol use is pretty much all on the motorway / dual carriageways.

 

[MusicLoverUK]

Last time I tested my passat GTE I averaged around 7l/100km (33mpg) on a motorway at 120kmh (75mph) with semi charged battery. My 500km+ trip averaged around 6.4l/100km (37mpg)

I think maybe you've used American gallons there. 7l/100km is about 40mpg (UK gallons) and 6.4l/100km is about 44mpg (UK).