What is the best economical speed for a 1.4CL Auto Polo when in D: Drive.

And the most economical speed whilst travelling on a motorway, if different.

Thanks in advance.

As with any car,you want it in the highest gear,and at the lowest revs that the car can comfortably hold. So when its in 4th gear,hold the throttle as high as you can without going under 50mph. It varies from car to car,depending on torque and gearing,but its generally between 45-65mph. A Polo auto will be best at about 50,as its not very long geared. Autos are adjustable,to change gear earlier.