First of all ,I hope everyone here can understand my pooooor English.
This is a test from a Chinese magezine called Modi-Auto.The tested tires are real RE070R from a stock R35 GT-R.

The tire surface temperature before test drive is 39.5°C.The durometer test result are:

Main pattern :62

Outer-side pattern: 65

Inner-side pattern:60

After a 30km test drive,the surface temp raised to 52.7°C,and the durometer reads

Main pattern :59

Outer-side pattern: 59 

Inner-side pattern:58 

I've know idea what kind of durometer they used.In fact I know nothing about durometerSmiley
.But there are 2 more groups of result from others tires for  a comparsion.

1.Bridgestone RE050A(215/45R17,comes from a Civic , not stock tires)

Before test drive:65(the middle pattern),  After:58.

The surface temperature was not tested,but is was really hot that day(The summer of South China) 


2.Bridgestone TURANZA ER300(205/55R16,Audi A4)

The middle pattern surface temperature:

Before testdrive 22°C         After :54.7 °C  

Durometer results:

Before test drive:middle 63,Inner and Outer 64.

After test drive:middle 59.