A station that is 60 won cheaper per liter can look like an automatic bargain. The story changes after subtracting the fuel your car burns and the time you spend. A complete calculation starts with price difference × liters and then subtracts the detour.
Key points
- Compare the same fuel grade, then calculate gross savings as the per-liter gap multiplied by liters purchased.
- Detour fuel cost is round-trip added distance divided by recent actual economy, multiplied by the reference fuel price; add tolls and waiting time separately.
- Check Opinet update time and operating status before departure, and do not search on a phone while driving.
Three-line summary
- Compare the same fuel grade and basis on Korea's Opinet, then check the displayed update time and station details.
- Gross savings equal `price gap per liter × liters`; detour fuel cost equals `round-trip extra distance ÷ actual fuel economy × reference fuel price`.
- Even 60 won/L cheaper saves only 2,400 won on 40 L. An 8 km detour can erase about half under the worked example below.
Information was checked at September 27, 2026, 21:04 KST. A return-trip fuel-discount story ranked third for JTBC and a highway-rest-stop price story ranked first for Seoul Economic Daily on Naver's publisher-specific most-read lists. These are publisher article readership ranks, not nationwide search rankings. Price meaning and update intervals were checked against official Korea National Oil Corporation Opinet guidance. Naver ranking news
1. Compare like with like first
Opinet uses sales prices reported by petroleum businesses under Korean law to provide station information. Match the grade—regular gasoline, premium gasoline, diesel or LPG—and check self-service status and travel direction. A station across a highway barrier may be close on the map but require a long real detour. About Opinet
The data is near-current, but it is not an absolute guarantee of the pump price at that second. Opinet says card-terminal prices are reflected at 1, 2, 9, 12, 16 and 19 o'clock, while direct reports appear immediately after entry or correction. Check details just before departure; if the gap is large, calling to verify hours and price is sensible. Opinet publication policy
Four-step detour calculation
Subtract the route cost from the displayed price gap.
- 01Match gradeCompare regular, premium or diesel
- 02Gross savingPrice gap × liters
- 03Detour costExtra km ÷ economy × price
- 04Final choiceSubtract tolls and time too
This is an editorial calculation diagram. All amounts below are a hypothetical example, not actual station prices, vehicle efficiency or tolls.
2. What a 60-won gap really saves
Assume the on-route station is 1,800 won/L, the detour station is 1,740 won/L, and you buy 40 L.
- Displayed gap: 60 won/L
- Gross fuel-purchase saving: 60 × 40 L = 2,400 won
- An 8 km round-trip detour, 12 km/L actual economy and 1,800 won/L reference price: 8 ÷ 12 × 1,800 = 1,200 won
- Net before time and tolls: 2,400 − 1,200 = 1,200 won
At a 16 km round-trip detour, fuel cost alone reaches 2,400 won under the same assumptions, erasing the price advantage. Traffic and tolls make it worse. If the station lies on the route, the detour cost is nearly zero and the gap survives.
3. Break-even table for your car
| Input | Example | Calculation or check |
|---|---|---|
| Price gap | 60 won/L | Compare the same grade |
| Purchase volume | 40 L | Use actual checkout liters |
| Round-trip extra distance | 8 km | Check added navigation distance |
| Recent actual economy | 12 km/L | Use the car display or fuel log average |
| Detour fuel cost | 1,200 won | 8 ÷ 12 × 1,800 |
| Time and tolls | Personal | Add queues, tolls and U-turn costs |
The break-even extra distance is:
`Break-even distance = (price gap × liters) ÷ reference fuel price × actual fuel economy`
Here, `(60×40) ÷ 1,800 × 12 = 16 km`. Beyond 16 km of extra round-trip distance, the benefit disappears even before valuing time and tolls.
4. What else to read on Opinet
Opinet provides regional low-price lists, nearby-station search, station details and national or regional averages. Read more than one price line. Opinet data list
1. Regular or premium gasoline, diesel or LPG 2. Price update time and operating status 3. Self-service availability 4. Real entry direction, U-turns and toll gates 5. Whether a card or membership discount applies to your payment conditions
Opinet data also feeds partner services such as Naver, Kakao and T map. Interfaces and update labels vary, so verify a surprisingly large gap on the source detail page.
5. Thirty seconds before departure beats searching while driving
Set the destination and candidate stop before moving, then compare added distance. Searching on a phone while driving carries a risk much larger than the possible saving. Ask a passenger or stop safely before changing the route.
Pre-departure checklist
1. Search the same fuel grade on Opinet. 2. Multiply expected liters by the price gap. 3. Read round-trip added distance and tolls in navigation. 4. Calculate detour fuel using recent actual economy. 5. Check operating status and price update time.
The cheapest posted station is not always the most economical stop. What reaches your wallet is the price saving minus detour fuel, tolls and time.