Thank you very much Cyrano, it seems that the Volotea aircraft have an MTOW which is right in the middle of the basic/HGW (49900kg vs 55900) although as you say Tagron this might not be 100% reliable. Volotea operate their A/C from a few runways less than 6,000ft, and even more between 6,000-7,000ft including on some flights up to 2.5 hours long.
I think that it seems as if they are the HGW variant, which have been certified below the maximum MTOW for the HGW variant, as you suggest to save money. Does this also mean that the range of Volotea's 717's will be somewhere inbetween the 1430nmi and 2060nmi?
Thank you