One of the very bad things you can do to your car is to drive hard before you have 3 bars on the temp gauge, mech told me that the oil wont stick to the parts inside the engine until the normal temp is reached and if you drive hard you would damage the pistons. Castrol made the Magnatex to prevent that.

 

oil temp takes a lot longer to move thant the water temp.. so having 3bars is not really full operating temperature of the engine/lubrication.. I normally give it a bit longer to bring up the oil temp to around 70-80C.

 

I guess a further search would have revealed the following information:

The S2000 has a very unique feature called a trunk monkey. It is this trunk monkey's job to hold a fuel cut-off kill switch in his hands. The engine rpm and temp gauge is wired into his gonads. When the revs get up to about 6000 and the temp gauge is below about 3 bars, the monkey gets a shock to his balls and he smacks his hand on his forehead.

 

ps. It is not necessary to have the engine at "operating" temps for the oil to be at a temp that is deemed adequate to be pumped at such speeds and such pressures. When the water temps gets to whatever it is at "3 bars", the oil temp is such that it's flow characteristics and lubrication dynamics is more than adequate to do the job it's asked to do. If you wish to wait, that is your choice. It is not necessary.