I have 2 hot fluids that need to be cooled. First is the water loop that is used to cool the motor and power electronics. The second is an oil loop used to cool a gear box. Both these will be cooled by air but two options are possible - 1) Cool both the water and oil in a traditional radiator (heat exchanger (HX)) with an airflow coming from a fan. 2) Cool the oil with the water first (the oil is at a much higher temperature and can be cooled by a liquid-liquid HX) and then cool the water as in (1).
The second option is essentially a HX within a HX. My question : Is there any obvious advantage to (2) over (1) ? By advantage, I mean in terms of overall weight and power consumption of the cooling schemes. Or to rephrase my question, thermodynmically which of the two is "better" ?