Mojo-tell me more about re-mapping and also its effect of fuel economy.
As you're getting more power earlier and better torque lower down so you have better acceleration from both standstill and overtaking.
Fuel economy will depend on how heavy your right foot is. In theory as you get better power lower down you don't have to be so right foot heavy in the first place to reach the same speed as before, so your fuel economy won't change too much. Naturally, the more right foot heavy you are the more fuel you'll use.
What some companies don't tell you is that your engine life is slightly decreased, but only by a few percent at most.
Normally a 1.9 remap will give you an extra 35 BHP on average. A 2.4 remap will get you around 45-55 BHP.
It all depends on your budget and your needs. If money is a concern remember a standard 2.4D costs over £2k more than a 1.9D already. Also, the insurance and road tax is more, and it drinks fuel quicker, costs more for servicing and the engine weight is a lot heavier (not good if you live in a speed hump area like I do). Increasing a 2.4D to 250BHP means a heck of a lot of power going to a FWD car. If you have that much power you should get a 4WD car like a Alfa with Q4.
If you think about it, the 1.9D is a lighter engine and gives you better fuel economy, less tyre wear etc. The saving in extra fuel and road tax alone in one year would pay for the majority of a remap of a 1.9D approx. You should knock a second off your 0-60 and improve overtaking capabilities.