I travel 7 miles each way to work everyday, it can be start stop depending on time. I'm averaging (according to cars computer) to be getting 30 mpg (+ or - 2/3mpg). On a recent run I did at a constant 80 mph it averaged out at 40 mpg. I'm not totally pleased to be honest but the car is still new and I'm told it will get better.
In comparison my 1.9tdi A3 got an average 40 mpg. It depends how many miles you travel over the year on whether or not it warrents spending the extra on a diesel. I don't have any regrets as of yet!, although driving a diesel is a different experience than petrol.
Might be looking at getting a map in the next 12 months to release the true potential.
I travel a similar distance to pns2007 each day in my 143ps 2.0tdi. I average around 48 mpg.
On a motorway run to the lakes at a steady 70, I averaged 55mpg.
The petrol will no doubt give you better acceleration, at the expense of fuel economy.
Good luck with your choice, I'm sure either would fit the bill.
suggest you buy a nissan micra ! On a serious note, in start/stop traffic the tdi does not even have time to get hot so it wont return good fuel ecconomy ! Buy a small engined petrol car for pottering in town and a big v6 tdi engine for good overtaking power and ecconomy on motorway ! Me a4 tdi quattro does 49Mpg on motorway and 35Mpg in town. I would say thats pretty decent for a car weighing at 1600kg...
I think you've got to go with the one you like the look of and which suits your driving style. Re-sale values, whilst important, come below the looks and feel of the car. You have got to enjoy it. I'd prefer the s-line over the SE (not because its diesel) but the SE does look a good spec. Any photos of them, have you driven either of them