Difference in rolling resistance asphalt and concrete.
It's been a hot summer, and my Space Star is showing high economy numbers. I am used to see 25 to 26km/L on the highway @100km/h, when the weather is right.
Last week I went to Belgium, and that opened a new dimension. On the outward journey I got in a traffic jam, which depressed the figures, but on my way back I got 28.4km/L. (About 100km Belgium and 25km Netherlands)
The main difference between the Dutch and Belgium highways is the the Dutch are made of Asphalt, and the Belgium are made of concrete. (And the roads in Belgium have some overdue maintenance, compared to the dutch.) So I wondered, concrete is harder than asphalt, so theoretically it could have a lesser rolling resistance. But could that give 10% difference?
View my fuel log 2013 Space Star Cleartec Intense 1.0 manual: 55.6 mpg (US) ... 23.6 km/L ... 4.2 L/100 km ... 66.7 mpg (Imp)