It's more than just a remap, it's a whole new fuel injection system with an even more finely measured fuel delivery. 'Multijet 2' is the official title. If indeed this is what the new 95 is - but I think so.
Both torque and performance, and economy, are improved. Particularly torque and emissions. For this reason I doubt it will be as laggy as the current 90, since the low end torque is enhanced.
I would hope that transmissions will be upgraded to cope; Fiat Powertrain is soon to bring a new automatic to production and I assume the other transmissions will get improvements too, or they could use the transmission currently fitted with the 1.6?
There is a 3 litre Diesel Multijet 2 coming soon which puts out only 150 carbon dioxides, which is less than my old 1.9 JTD. Fantastic. So you can see the improvements the new engineering will bring. And this is before they fit the Multiair valve system to the Diesels in a couple of years. Actually Multiair seemingly delivers smaller improvements with Diesels as they are inherently more economical.
But, by this time next year I'd expect all Fiat petrol engines to be the new Multiair twins up to about 105 BHP, and the Multiair 1.4s and 1.8s above, probably all with direct injection too. The 1.8 arrives with the Mito later this year, without Multiair but with direct injection. Give it a year and the engine range will be equalled across the board with all having the improvements.
This is my take on the Powertrain developments anyway.
PS. You can see why Fiat has such good prospects in the US, particularly as they have just introduced new CAFE requirements.