How should I compare Safar's upfront price and its ongoing oil against a passive format?

A cost comparison with one column missing is still worth drawing. The missing column is the honest part, and a marker pen on a 20ml bottle fills it in a month.

The answer, in full

Draw two columns and accept that only one of them can be filled in today. The upfront column is published and exact. Safar is ₹3,999, or ₹4,499 for the hotel-inspired variant. A hanging bottle is Jasmine ₹459 at the lower end of the range and Oud, Vetiver or Sea Breeze ₹519 at the higher end. Eight Jasmine bottles at ₹459 come to ₹3,672, which sits ₹327 below the Safar figure, and that is the whole of what the upfront comparison says. The ongoing column is where it stops. SOSA publishes the refill price and no oil-consumption rate, so no cost per month, per journey or per operating hour exists, and no refill interval exists either. That means the second column of your comparison cannot be completed by me, by the product page or by anybody else, and a page that filled it in would be inventing the number. What can be said about the ongoing side is price, not rate: nebuliser refills are ₹1,049 for 100 gm and ₹1,849 for 300 gm, and 15ml hanging refills are ₹399 to ₹449 across eight scents. Comparing the two nebuliser sizes is arithmetic on two published prices, so it is allowed: ₹1,049 for 100 gm is ₹10.49 per gramme and ₹1,849 for 300 gm is about ₹6.16 per gramme, and three 100 gm tins come to ₹3,147 against ₹1,849 for the same 300 gm. The nebuliser refill is sold in grammes and the hanging refill in millilitres, so those two cannot be put on one axis either. Mark the oil level on the 20ml bottle with a marker pen on the day you start, write the date beside the mark, drive your ordinary month, then mark it again. That is the only consumption figure that will ever be true for your driving. A portion of every SOSA order supports girl-child education through Nanhi Kali.

Two columns: the one that can be filled, and the one that cannot

This is a cost question with an honest answer and an honest gap. I have done every sum the published prices allow, and I have marked the point where a published figure would be needed and does not exist.

The upfront column: published, exact, and comparable

Safar is ₹3,999, or ₹4,499 for the hotel-inspired variant. The hanging format runs Jasmine ₹459, Lavender and Sandalwood ₹499, Icy Mint ₹499, Sandalwood ₹509, Lemon ₹509, and Oud, Vetiver and Sea Breeze at ₹519. Eight Jasmine bottles at ₹459 come to ₹3,672, ₹327 below the Safar figure; seven at ₹519 come to ₹3,633. A 50ml spray is ₹1,509 on any scent. Those are all published prices and every sum between them is arithmetic.

The difference between Rs 3,999 and Rs 459 is Rs 3,540.

The ongoing column: where the comparison stops, and why

What the ongoing side needs is a rate: how much oil a Safar uses in a week of your driving. SOSA publishes the refill price and no oil-consumption rate, so no cost per month, per journey or per operating hour exists, and no refill interval exists either. The 2000 mAh battery publishes up to ten hours continuous or thirty hours intermittent per charge, and that is the battery per charge, never a measure of the oil. On the hanging side the published figure is a window rather than a rate - 4 to 6 weeks, that is 28 to 42 days, of continuous diffusion per 12ml bottle - and a window for one bottle is not a consumption rate for the other format. So the second column is blank, and it should look blank.

What is comparable on the refills: the two nebuliser sizes, by published price per gramme

Both nebuliser prices are published, so the sizes compare directly. ₹1,049 for 100 gm is ₹10.49 per gramme. ₹1,849 for 300 gm is about ₹6.16 per gramme. Three 100 gm tins come to ₹3,147 against ₹1,849 for the same 300 gm, a difference of ₹1,298 on the published prices. That is price per gramme and nothing more: it says which size carries the lower published price per gramme, and it says nothing about how long either lasts, because no rate is published. The 15ml hanging refills at ₹399 to ₹449 are sold in millilitres and cannot be put on the same axis.

Price per gramme is arithmetic. Price per month is not.

Scent, which the cost columns do not touch

Eight of the nine car scents come as a 10ml spray or a 12ml hanging at the same price per scent, so the format decision and the scent decision are separate sums. SOSA publishes no strength ranking of the nine and no prediction of what anybody will prefer, so no scent on either side of the comparison can be said to go further per rupee. Mysore Orange Blossom ₹559 is a spray only.

The nebuliser refills carry both published sizes, ₹1,049 for 100 gm and ₹1,849 for 300 gm, and the per-gramme sum above is the only comparison between them that exists. See the nebuliser refills →

The comparison, column by column

If another page offers you a monthly running cost for a Safar, ask where the consumption rate came from. There is no published one, so the figure was either measured on somebody else's commute or invented, and neither is yours. SOSA publishes no ranking of the formats by how much work they feel like, so that part of the decision is yours.

“The upfront half of this sum is exact. The ongoing half does not exist yet, and a marker pen is cheaper than a guess.”

Filling in the column nobody can publish

1. Fill the upfront column from the published prices. That part is exact.
2. Mark the oil level on the 20ml bottle and write the date beside the mark.
3. Drive an ordinary month. Change nothing else about how you run it.
4. Mark it again. Now your ongoing column has a number, measured not guessed.

Questions, answered