Hetman oils are the best.
They are synthetic, so offer very smooth performance, good instrument protection and there are no unpleasant or carcinogenic aromas to inhale.
Numbers 11 and 11.5 both make tight fitting valves move quickly and smoothly.
11 is the ultimate light oil for quick valves but will evaporate in 1 to 1.5 weeks.
11.5 is slightly heavier, still gives very quick valves but can last 1.5 to 2 weeks between oiling.
Use 11 in cold climates/seasons and 11.5 in hot climates/seasons.
The full range of Hetman oils and greases are mutually compatible so can be used throughout the instrument without any reaction issues.
NB: Different oil types shouldn't be mixed. If mineral oils have been used previously in your instrument, these may be removed using a light organic solvent (eg lighter fluid), followed by detergent rinse and water flush. Then you're ready to start using the Hetman oils :)