Since majority of your usage is over well-paved highways, I would suggest that you go for Yokohama Geolandar H/T. It would perform well over highways as well as rough/ uneven roads.
In case you want something better then go for Michelin Latitude Tour HP would be a great option. It offers excellent traction, comfort and has long tread life- very much suitable for highway rides.
My 7 year old Scorpio - mahindra make, needs all tyre replacements.my usage is both on and off road and both wet and dry surfaces. My current oem size is 235/70/R16. Which is the best choice? Is an upsize advisable and if yes please suggest the most suitable one. Thanks and regards.
Considering your usage I will suggest you Bridgestone Ecopia EP850 tyre. These are low-rolling resistant tyres that can improve the fuel efficiency of your vehicle by 10% without compromising the performance. If you want to upsize then you can consider 255/65R16 size also as the diameter variance compared to the original size is just 0.76.