I was worried that fitting a Radiator Guard might cause the engine to overheat in traffic. But so far it has managed to still keep cool enough (even in Italy stuck in traffic)
I also have R&G guard. technically it can reduce the flow when you are on the move but I don't think it does so at slow speed or stationary. Mine runs at 77 on normal runs maybe higher at higher speeds. On warm days (23+) this can creep into low 80's at high motorway speeds. At low speed and in traffic, it just shoots up but the fans kick in sequentially and keep all under control I use 10/50 FS oil, in my experience it reduces engine heat
I also use a higher viscosity oil 10w/40 to help with engine temps in London sodding traffic. Would love to find a way of making the fans come on earlier
I would.t worry about changing these. What's important is they come on when they are supposed to. What you can do is to go 10/50 and this will reduce the heat hike and also in warm weather, long term provide more protection. From experience, you can overheat in the legs and private departments! I have no solution. You can try removing the plastic side cover under the seat and tell us if it makes any difference. I would be interested to know as my was really hot above 25 deg last year. Hats off to you guys riding a CBR in london
