Yes also the same case with my cruise control in Aqua which is factory fitted.
Although on motorway the ideal speed for the car is 105 so even 115 is more than enough.
On 115 the car will give 22-23 km/l but on 100-105 it gives 24-25 km/l.
So its better to set it somewhere around 100-107 and not even set it at 115. You maybe save 20 minutes pushing it past 115 and lose out on so much fuel as a result. This is also the case with most cars.
