I drive the new Atrai and would like to add Bell Hammer Light in two half doses instead of all at once. Would the effect be similar? I’m cautious because a previous additive raised the oil above the HI mark.

The engine oil capacity for the new Atrai (S700V / S710V) is as follows:

Without oil filter replacement: approx. 2.6L

With oil filter replacement: approx. 2.8L

The recommended additive ratio is 5–10%.
If calculated at 5%, the amount would be:

2.6L × 5% → approx. 130ml

2.8L × 5% → approx. 140ml

Therefore, using a total of 260ml divided into two separate doses (130ml each) matches the recommended amount and is both safe and effective.
As you mentioned, splitting the additive into two applications helps avoid exceeding the “HI” mark on the oil gauge, making this approach reasonable.

The benefits such as improved lubrication and reduced engine noise should still be noticeable as the protective film gradually forms, so you can use the product with confidence.