48mm Marzocchi PFP fork oil

[Anders]

Experts,

On my new (to me) 2015 EC200 I feel that the fork works quite well, but could have been somewhat plusher (for my ability and speed). I am quite certain they have not been serviced yet, so I presume OEM oil and viscosity and level. Although I do not know the number of running hours from the previous owner, I presume the bike has run between 20 and 40 hours now. Ergo it is soon time for an oil change in the forks. The forks should (per the documentation) have 7.5W oil.

My simple question is: how much would a lighter oil (I usually use ?hlins 5W) affect the damping? Would it be like 5 clicks or 10 clicks? Or more?
The reason for asking is that I am now at max clicks out on the compression and also more than 15 clicks out on rebound. Hence if using 5W oil could give me the equivalent of say 10 clicks, I could happily set my forks at say 10 clicks compression and 5 clicks rebound and proceed without any revalve

I understand that lighter oil will also affect the HS compression, but I am quite sure I can live with that.

Of course the real answer can only be found by trying it out, but if someone here has a rule of thumb I could use, I would be glad to learn about it.