So it will not change anything if I use a 1.50 coil ?
Your original topic was with regard to a 'subtank' which, one would imagine, refers to a 'sub-ohm tank, which, if you use a 1,5 ohm coil, it wouldn't be.
In answer to your question, however is yes. It would be easy enough to try it to see but if you do so, you'll have to lower the wattage as well. Only you can determine if you find the combination satisfying compared to whatever amount you may lower your e-liquid consumption. This question is critical if you are trying to quit cigarettes or have recently stopped smoking.
If you'd allow a slightly off-top suggestion, take a look at the extensive DIY juice section here at VU. Easy and inexpensive to get started and you will lower you cost of e-liquid to a degree that usage is no longer a concern.