Bunker One vs Saybolt Viscosity
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Bunker One
This app provides a suite of calculators for marine fuel standards, including CCAI, Cetan Index, and blending calculations. It supports ISO 8217 and ASTM standards, with all inputs and outputs in SI units. Users can also access news and updates from the developer.
- ISO 8217 fuel standard lookup
- CCAI Number calculation
- Cetan Index calculation (old & new methods)
- Fuel blending calculators (viscosity, sulphur)
- Injection temperature calculation
- Energy and price relation calculations
- News updates from developer
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This application by Bunker One, is a small practicable tool for look up the ISO 8217 - 2005, 2010/2012, 2017 & 2024 standards for residual- and distillate marine fuels. Programmed calculators are included for different fuel related calculations. Calculators programmed as below.: -CCAI Number according ISO 8217 -Cetan Index ASTM - D 976 - 80 (old method) ASTM - D 4737 - 87 (new method) -Deviation calculations according Bunker One -Energy and price relations according Bunker One -Fuel Blending - Viscosity blending according ASTM - D 7152 Sulphur blending according Bunker One -Injection temperature according Bunker One -Reproducibility -Specific Energy gross and net content according ISO 8217 -Viscosity Index according ASTM - D 341 -Volume Correction Factor according ASTM D1250-80 Table 5B General for all calculators is that all entries shall be in SI units. And results also given in SI units. Where there is a differentiation between Distillates and Residual fuels, distillates are defined with density lower than 900 kg/m3 Where there is a differentiation between Straight Run fuel and Cracked fuels, straight run fuels are defined with density lower than 950 kg/m3 News published on our web page Bunkerone.com will be pushed to the app holders and publish with link to the web under the "news" bar
Saybolt Viscosity
This application serves as a calculator for converting viscosity and temperature values for petroleum fuels. It allows users to convert Kinematic Viscosity in Centistokes to desired target values across different temperature scales. In landscape mode, it transforms into a slider for visual comparison of viscosity units.
- Viscosity/Temperature conversion calculator
- Converts Kinematic Viscosity (cSt)
- Supports Fahrenheit and Celsius
- Landscape slider for unit comparison
- Compares Centistokes to Saybolt Universal Seconds and Furol
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Welcome to the Viscosity/Temperature conversion app developed by Saybolt. This App is a handy Viscosity/Temperature conversion calculator for petroleum fuels. The calculator converts the Kinematic Viscosity in Centistokes (cSt) at a reference Temperature in Fahrenheit or Celcius to the desired target value. The App changes into a traditional Viscosity/Temperature slider when the mobile device is held in landscape position. By reading the slider scale under the hairline Kinematic Viscosity units can be compared, such as the Saybolt Universal Seconds or Saybolt Seconds Furol, with the nowadays more widely used Centistokes. Temperature and viscosity conversions with the slider are indicative.
Screenshots
Verdict
The clearest difference is rating: Bunker One at 4.5 against Saybolt Viscosity's 3.0. Bunker One also leads on update cadence (every 3 months vs every 14 months). Saybolt Viscosity's advantage is iOS requirement (9.3 vs 15.6). On price, ratings volume, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Bunker One holds the better App Store score, 4.5 against 3.0. Both are backed by a comparable volume of ratings — 2 and 2 respectively.
Bunker One ships an update every 3 months, Saybolt Viscosity every 14 months. Both last shipped on October 23, 2026.
| Parameter | Bunker One | Saybolt Viscosity |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (2 ratings) — better | 3.0 (2 ratings) |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 2 | 2 |
| Update frequency | Every 3 months — better | Every 14 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 15.6 | 9.3 — better |
| Further details — not scored | ||
| Size | 16 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Askapps | Saybolt International B.V. |
Customer experience
Bunker One
Saybolt Viscosity
In-app purchases
Bunker One
No in-app purchases
Saybolt Viscosity
No in-app purchases
Questions
Is Bunker One free?
Is Saybolt Viscosity free?
Which has better reviews, Bunker One or Saybolt Viscosity?
Do Bunker One or Saybolt Viscosity have ads?
Which is updated more often, Bunker One or Saybolt Viscosity?
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