The online racing simulator
If you go to a co that chip tunes, then they have done research, generally. And ALWAYS do oil changes at half the approved intervals and get it serviced. Look at the air intake as well, a high quality air filter will often give a good improvement on performance.

It's like overclocking a pc, officially, never do it. Unofficially, done right, it can give a large improvement over stock settings that are "stock" for a very good reason. ( Big co, want to limit warrenty issues so tune it down for cost reasons )

I run a Mitsi V6 with a K&N and improved breathing & exhaust, I've got better fuel economy and more power..........
I haven't bothered rechipping as I'm happy with what I've got for the road. ( And the ECU adjusts for breathing changes. )
I put in a Revo Ecu upgrade in my Audi A3 2.0T best money ever spent, Fuel economy increased massively (9L per 100kms to about 6.5L) and the power gains where absolutely insane, 200hp to about 270hp.

Companys like this are just optimising the cars engine map so its isn't running the incredibly Rich stock setting, I would avoid those Chip Tuning boxes that you just connect to your cars ECU and stay in the engine, haven't heard anything good about them.

Ill tell you now though, unless your car has Forced Induction, its a complete waste of time doing this as the power gains will be very minimal.
About the fuel eco - did they upgrade the driving computer (if this car has it?) aswell? Because from what I'v heard the driving computer will show the incorrect numbers if that aswell is not updated with the new powers.

But as for now it's kind of on hold due to various reasons. I talked with the incurance company about the matter and how they would stand in this. They simply said that if any modifictions was done to this car = ban from the insurance Tried talking some reason with them but nope, not going to happend.

So before I aproach them first I will have to send some applications to the norwegian roaddepartment (no idea what it's in english is called, but the place where you get everything from license plates to other papers for your car) with confirmation letters from mazda that the car is supported for the new setting ASWELL that the toll customs needs some papers aswell Then, and only then, would the incuranse company be a "maybe" and most likely more costly.
You're a very honest man TVE.

Normally, you simply install the chip and don't tell your insurance company...
Quote from The Very End :About the fuel eco - did they upgrade the driving computer (if this car has it?) aswell? Because from what I'v heard the driving computer will show the incorrect numbers if that aswell is not updated with the new powers.

Mustafur is talking about a petrol engine. Turbocharged petrol engines usually run on a rich mixture ratio to keep the combustion temperatures low. If you lean the mixture out you're obviously going to get better fuel economy. This is obviously not the case with diesel engines.
There's wot u tell your insurence co and wot u don't.
Chipping the car gives u a better car, but .....

If they don't pick up a better car and you aren't planning on making a claim to rip them off, no problem.

Everything else is your problem.
-
(Wenom) DELETED by Wenom
Chip tuning can be worthwhile, however, don't expect massive gainzz on a 1.6 diesel.
Cars are often made to be able to run on shit fuel under shit conditions. These conditions differ per country, so I'd advise you to search locally. Since Norway can be quite cold, I wouldn't expect a huge improvement.
2

FGED GREDG RDFGDR GSFDG