# Saybolt Viscosity vs Transport4

The clearest difference is rating: Transport4 at 5.0 against Saybolt Viscosity's 3.0. Transport4 also leads on update cadence (every 2 months vs every 14 months). Saybolt Viscosity's advantage is iOS requirement (9.3 vs 16.6). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Transport4 holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Saybolt Viscosity ships an update every 14 months, Transport4 every 2 months. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Saybolt Viscosity | Transport4 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (2 ratings)](https://appshunter.io/ios/app/saybolt-viscosity/id631153914/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/transport4/id6538714499/reviews)** |
| Number of ratings | **2** | 1 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 14 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 3 MB | 35 MB |
| Requires iOS | **9.3** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Saybolt International B.V.](https://appshunter.io/developer/493919167) | [Transport4](https://appshunter.io/developer/1701539376) |

## What reviewers say

### Saybolt Viscosity

[App page](https://appshunter.io/ios/app/saybolt-viscosity/id631153914)

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.

**Highlights:** 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

**In-app purchases:** none


### Transport4

[App page](https://appshunter.io/ios/app/transport4/id6538714499)

Access your work schedules, nominations, and tickets on the go. Customize your view to see only the data relevant to your security profile. This business tool streamlines access to essential information from your mobile device.

**Highlights:** Access nominations, View schedules, Manage tickets, Customizable profiles, Mobile access

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Saybolt Viscosity free?

Saybolt Viscosity is free to download, with no in-app purchases.

### Is Transport4 free?

Transport4 is free to download, with no in-app purchases.

### Which has better reviews, Saybolt Viscosity or Transport4?

Transport4 is rated higher. Saybolt Viscosity averages 3.0 out of 5 from 2 ratings, while Transport4 averages 5.0 from 1 ratings.

### Do Saybolt Viscosity or Transport4 have ads?

Neither Saybolt Viscosity nor Transport4 shows ads.

### Which is updated more often, Saybolt Viscosity or Transport4?

Saybolt Viscosity ships an update every 14 months, and Transport4 every 2 months. Most recently, Saybolt Viscosity was updated on November 1, 2026 and Transport4 on November 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*