Thats not too bad to be honest.
You've got to considering 1.2 wont really be economical at 70mph, Your looking at about 4500rpm. If you were travelling at 50mph for example you'd get alot more.
1.2s are not fantastic at motorway miles, You want to look at the 1.9TDI PD100, Cheap on insurance and great on the motorway,