Route results returned from Here maps routing api version 7 & version 8 are different. Can someone share reason for this?

Question

Route results returned from Here maps routing api version 7 & version 8 are different.

V7

url:

https://route.api.here.com/routing/7.2/calculateroute.json?app_id=<API_ID_VALUE>&app_code=<APP_CODE_VALUE>&waypoint0=geo!45.5,-100.7&waypoint1=geo!34.698,-108.6&mode=fastest;car;traffic:disabled&alternatives=2&maneuverAttributes=shape

No of routes: 3

Route distance calculated from V8

1. 1834305
2. 1925430
3. 1922465

V8

url:

https://router.hereapi.com/v8/routes?apiKey=<API_KEY_VALUE>&origin=45.5,-100.7&destination=34.698,-108.6&routingMode=fast&transportMode=car&alternatives=2&return=actions,instructions,summary,polyline,travelSummary&spans=length

No of routes: 3

Route distance calculated from V8

1. 1835187
2. 1925571
3. 1909457