wow thats a " big " dilution rate there. You can dilute it as much as you want . Try some tests on a small scale to see what look or economy dilution you're looking for. I used to dilute mine by about 10% to 20% but got some streaking onetime on some plastic trim and sometimes I would forget if I diluted my product already so I went back to using it straight up.
I would say a dilution of more than 30 % water would lose on protection , cleaning power and overall look of natural Look.
If you're diluting it to save money, you COULD dilute BnB 3:1....which pretty much yields NL. You don't get that cool scent, though....oh....and it's not BLUE, anymore.