Wheels and tyres

Hey guys , 
Long time since i uploaded my last post .
I need your opinion ... I have changed my wheels and tyres on my 2002 m13A jimny . 15"x8" steel wheels with 215/75/15 A/T's .. i have seen a drastic change in handling but also the car is much heavier now and max speed is 120km/h .. thats not the problem though . I live in cyprus so the temperatures are high in the summer and lately i noticed that my temperature gauge when the car is on hill climb or after a stressful ride it goes just under the red zone .(very high in my opinion") bunt never in the red zone and in 3rd gear the car drops the temperature .. (2nd 4th and 5th gear increase temperature on hills ) .. after all i connected an obd reader and when the temperature gauge is so high just under red zone the ecu says that tha the temperature is 106 Celsius ... Is this normal or is my gauge faulty .. And also does the overheating problem is from bigger heavier wheels ?if i change to aloys it will be better ?  What ate your thoughts?(no coolant leaks , new radiator water pump cap etc.)

Thank you very much for your time .

I can see how the wheel size change is making the engine work harder which generates more heat. But I tow caravan for hours on end, most of the time at full throttle and not traveling very fast, so it's got to be worse or equal to the wheel size change. What I have never seen is any sign of temperature increase or overheating, the gauge stays "normal" no matter how hard I push it. Makes me think something is not 100% with your cooling system.
Not sure what to suggest as your radiator is new. Possible gauge fault?
Hopefully someone will confirm ODB temperatures, it's not something I've looked at.
 

I have an OBD reader connected 24x7 (Torque Pro) and the coolant temperature on OBD matches the dashboard gauge all of the time, so you might have a faulty gauge.

The high temperature in one gear is a bit odd, does the OBD coolant temperature get to 106 in other gears, but the gauge reads correctly?

Hi DrRobin,
Is the torque pro you have the ELM327 and you leave it connected?
Must get something a bit more portable than my garage ODB unit and don't mind an app based device in the car, just in case.
TaMike