# Trans4motor vs Automobile Engineering Book

The clearest difference is price: Automobile Engineering Book at Free against Trans4motor's $2.99. Automobile Engineering Book also leads on review sentiment (100% vs 57%) and rating (4.6 vs 3.7). Trans4motor's advantage is ratings volume (70 vs 9). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Automobile Engineering Book is free to download; Trans4motor costs $2.99 up front. Trans4motor sells 1 one-off in-app purchase and Automobile Engineering Book sells 4 in-app purchases, starting at $2.99 per 3 months. Whichever you choose, the download price is not the number that matters.

Automobile Engineering Book holds the better App Store score, 4.6 against 3.7. That said, the two scores are not equally well evidenced: Trans4motor has 70 ratings behind it against 9, so its average is the more settled of the two. Written reviews point the same way: 57% of Trans4motor's written reviews are positive against 100% of Automobile Engineering Book's.

Trans4motor ships an update every 2 months, Automobile Engineering Book every 5 weeks. The most recent releases landed on September 26, 2026 and August 4, 2026 respectively.

## The numbers

| Metric | Trans4motor | Automobile Engineering Book |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [3.7 (70 ratings)](https://appshunter.io/ios/app/trans4motor-engine-simulator/id899277186/reviews) | **[4.6 (9 ratings)](https://appshunter.io/ios/app/automobile-engineering-book/id1583758958/reviews)** |
| Number of ratings | **70** | 9 |
| Positive reviews | 56.6% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 24 MB | 136 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kitt Peak, Inc.](https://appshunter.io/developer/399507326) | [Oleksandr Pereshein](https://appshunter.io/developer/1041461209) |

## What reviewers say

### Trans4motor

[App page](https://appshunter.io/ios/app/trans4motor-engine-simulator/id899277186)

Explore the mechanics of 4-stroke engines with this interactive simulator. Visualize the transformation of various engine types and understand their internal workings through detailed CG animation. Enhance your knowledge with adjustable settings and realistic engine sound options.

**Highlights:** Multi-cylinder engine transformation, Realistic engine sound (in-app purchase), Accelerator control simulation, Expandable engine library, Custom engine registration and editing, Interactive educational videos

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Add Engine Sound | $1.99 | one-time |


### Automobile Engineering Book

[App page](https://appshunter.io/ios/app/automobile-engineering-book/id1583758958)

This app provides a comprehensive yet accessible guide to automobile engineering. It covers basic vehicle structure, common malfunctions, and maintenance rules in a clear, engaging format with ample illustrations. Ideal for novice drivers and anyone seeking to understand their car better.

**Highlights:** Basic vehicle structure information, Common malfunctions and solutions, Operation and maintenance rules, Simple language explanations of car systems, Extensive illustrative material

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full version | $2.99 | per 3 months |
| Full version for three months | $2.99 | one-time |
| Full version for one year | $4.99 | one-time |
| Full version forever | $6.99 | one-time |


## Frequently asked questions

### Is Trans4motor free?

Trans4motor costs $2.99, and also offers in-app purchases.

### Is Automobile Engineering Book free?

Automobile Engineering Book is free to download, with in-app purchases available.

### Which has better reviews, Trans4motor or Automobile Engineering Book?

Automobile Engineering Book is rated higher. Trans4motor averages 3.7 out of 5 from 70 ratings, while Automobile Engineering Book averages 4.6 from 9 ratings.

### Do Trans4motor or Automobile Engineering Book have ads?

Neither Trans4motor nor Automobile Engineering Book shows ads.

### Which is updated more often, Trans4motor or Automobile Engineering Book?

Trans4motor ships an update every 2 months, and Automobile Engineering Book every 5 weeks. Most recently, Trans4motor was updated on September 26, 2026 and Automobile Engineering Book on August 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.*