# Engine RPM vs Microdyno

The clearest difference is review sentiment: Microdyno at 100% against Engine RPM's 48%. Microdyno also leads on update cadence (monthly vs every 16 months). Engine RPM's advantage is monetization model (free vs paid) and iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Engine RPM costs $8.99 and Microdyno $8.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Engine RPM ships an update every 16 months, Microdyno monthly. The most recent releases landed on October 27, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Engine RPM | Microdyno |
| --- | --- | --- |
| Price | $8.99 | $8.99 |
| Rating | **[4.0 (35 ratings)](https://appshunter.io/ios/app/engine-rpm/id340401811/reviews)** | — |
| Number of ratings | **35** | — |
| Positive reviews | 47.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 16 months | **Monthly** |
| Monetization | **Free** | Paid |
| Size | 3 MB | 108 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Real-Time Specialties](https://appshunter.io/developer/335568332) | [Stefan Hurzlmeier](https://appshunter.io/developer/969804263) |

## What reviewers say

### Engine RPM

[App page](https://appshunter.io/ios/app/engine-rpm/id340401811)

Analyze engine sound to calculate RPM using advanced signal processing. Ideal for engine setup and diagnostics, it supports various engine types and provides real-time feedback for accurate readings.

**Highlights:** Acoustic RPM measurement, Engine sound analysis, Supports 2-stroke/4-stroke engines, Configurable cylinder count, Real-time autocorrelation graph, Adjustable update periods, Low-pass filtering

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💰 Saves money vs. dedicated tachometer
- 🛠️ Useful for engine tuning/diagnostics
- ✅ Works well with correct settings
- 🏎️ Accurate for steady RPMs
- 💡 Ingenious app concept

**What reviewers complain about**

- 📉 Inaccurate or unreliable readings
- ❓ Difficult to configure/use
- 💸 Waste of money (for many)
- 😵 Confusing interface/settings
- ⚡ Not good for rapidly changing RPMs

**Reported bugs**

- Does not register live RPM readings
- Displays incorrect or random numbers
- App opens then closes immediately
- Blank display or flashes incorrect data intermittently
- Cannot get consistent readings

**Requested features**

- Save configuration settings
- Option to display cycle/cylinder count on home screen
- Improved response time for transient surges
- Simplified or automated setup process
- Auto-scaling graphical display for easier harmonic matching


### Microdyno

[App page](https://appshunter.io/ios/app/microdyno/id6749821546)

Transform your iPhone into a professional dynamometer. This app uses advanced audio analysis to precisely measure vehicle performance and torque in real-time without expensive hardware. It offers detailed vehicle profiles, weather integration, and professional data visualization.

**Highlights:** Real-time performance measurement (PS, Nm, RPM, speed), Over 100 pre-configured vehicle profiles, Automatic weather data integration for correction, Harmonic editing for cleaner results, Professional data visualization and export, Customizable vehicle profile creation, Measurement history tracking

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

**In-app purchases:** none


## Frequently asked questions

### Is Engine RPM free?

Engine RPM costs $8.99, with no in-app purchases.

### Is Microdyno free?

Microdyno costs $8.99, with no in-app purchases.

### Do Engine RPM or Microdyno have ads?

Neither Engine RPM nor Microdyno shows ads.

### Which is updated more often, Engine RPM or Microdyno?

Engine RPM ships an update every 16 months, and Microdyno monthly. Most recently, Engine RPM was updated on October 27, 2026 and Microdyno on October 28, 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.*