And diesels are the fuel of Satan.
Get the petrol. Screw the mpg and enjoy the TS scream at 5k to 7k.
I went from a diesel to the 1.6 petrol. And yes it does less mpg, and there's hardly any mid range compared to a turbo car. But keeping the small engine on the boil is all part of the fun. And no one want to hear a diesel going flat out. It's just like a tractor racing past.
To be fair though alfa fiat group have made some fab diesels. But if I was you I'd look at how many miles you soma year. Anything less than 10k get the petrol. Anything over and the diesel will be the safer bet.
The petrol models will be cheaper to buy and maintain. The diesels will be more expensive but you can claw back the savings in a couple of years depending on how long you own it.