What is the original size tyres for my 2006 pajero 3.2diesel lwb

Instead of what size?

Fewer professional tyre fitters these days will deviate from fitting tyres of the original size and spec. due to them being the expert in the contract and therefore bear the greatest share of responsibility should anything go wrong.

Many insurers these days consider fitting tyres of non-original size and spec to be a notifiable modification. If the insurer isn't notified of such a modification, they will be entitled to withdraw all or part of their cover in the event of something going wrong.

In the aftermath of a collision or other type of accident the police tend to examine the vehicle tyres first...

The wheels could have been changed on the car from the standard original factory set and hence the tyre size may not be the standard factory original size.
The size of the tyres on the vehicle now is moulded into the side wall of the tyres and is easy to read.
Check all 4 tyres because larger size tyres may have been fitted as a pair to the rear.

The size might read - for example 245 45 18 or 235 45 17 (there are a huge number of sizes for each model of tyre).

The first 3 numbers are the width of the tyres in mm eg 225 mmm or 235 mm and so on. The second 2 numbers are the tyre profile size or ratio (which can be 70 65 60 55 50 45 40 and so on. The third number is the wheel diameter size. If you have 18 inch wheels on the car the tyres will read 18 or if they are 17 inch wheels the tyres will read 17 and so on.

http://www.jaxquickfit.com.au/tyres/vehicles/daihatsu/charade#2006 Click on link to find your tire size and brand.

check wheel and tyre sizes with the homoglonation certificate ,could be that the profile on the tyres is the wrong size .

What pressures are you running in the tires that are giving you the problem?

16 is the rim size and most modern ones will take 215 tyre. Of more concern is the PCD (which dictates how holes line up) would suggest a trip to a breakers and get 4 from any VW Passat (or other) of similar age

go to your local Bridgestone tire dealer and ask to see the Turanza with Serenity. They are great tires and have low road noise.

standard is the size 15 inch x 195

That is 1.4 metric tons, that is allot of weight, that is the problem, not the trans type, you are really pushing the limits of the SUV's tow capacity. Careful or you will burn up the transmission.