# bmTuned vs DiagonalOBDII

The clearest difference is rating: DiagonalOBDII at 5.0 against bmTuned's 3.0. DiagonalOBDII also leads on update cadence (every 2 weeks vs every 7 months). bmTuned's advantage is in-app purchases (none vs 4) and device support (4 vs 1). On price, ratings volume and ads there is nothing between them.

Both are free to download. DiagonalOBDII sells 4 in-app purchases, starting at $12.99 per month. bmTuned asks for nothing beyond the download.

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

bmTuned ships an update every 7 months, DiagonalOBDII every 2 weeks. The most recent releases landed on September 14, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | bmTuned | DiagonalOBDII |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (2 ratings)](https://appshunter.io/ios/app/bmtuned/id1625950793/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/diagonalobdii/id6743419784/reviews)** |
| Number of ratings | **2** | 1 |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 13 MB | 21 MB |
| Requires iOS | **15.6** | 18.1 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [OddsMedia, LLC](https://appshunter.io/developer/1543533404) | [Kyle Louderback](https://appshunter.io/developer/1400068218) |

## What reviewers say

### bmTuned

[App page](https://appshunter.io/ios/app/bmtuned/id1625950793)

This platform allows BMW owners to customize their vehicles' engine control units (ECUs) and automatic transmissions (TCUs). It also enables seamless conversion between AWD and RWD modes for supported xDrive models.

**Highlights:** ECU tuning for N54, N55, N13 engines, Flash off-the-shelf maps, Adjust automatic transmission settings, Customize AWD xDrive vehicles, Convert between AWD and RWD modes

**In-app purchases:** none


### DiagonalOBDII

[App page](https://appshunter.io/ios/app/diagonalobdii/id6743419784)

This app helps mechanics perform vehicle drive cycles more efficiently. It provides real-time monitoring of emissions monitors and diagnostic trouble codes (DTCs), offering clear guidance and instant explanations to ensure vehicles pass inspection quickly and accurately.

**Highlights:** Live drive cycle monitoring, Immediate diagnostic trouble code (DTC) identification, Real-time emissions monitor status, Precise drive cycle parameter guidance, Professional, easy-to-navigate dashboard, Instant code explanations

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Diagonal Premium Monthly | $12.99 | per month |
| Diagonal Premium Trial | $12.99 | per month |
| Shop Owner - Monthly | $17.99 | per month |
| Diagonal Premium Yearly | $99.99 | per year |


## Frequently asked questions

### Is bmTuned free?

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

### Is DiagonalOBDII free?

DiagonalOBDII is free to download, with in-app purchases available.

### Which has better reviews, bmTuned or DiagonalOBDII?

DiagonalOBDII is rated higher. bmTuned averages 3.0 out of 5 from 2 ratings, while DiagonalOBDII averages 5.0 from 1 ratings.

### Do bmTuned or DiagonalOBDII have ads?

Neither bmTuned nor DiagonalOBDII shows ads.

### Which is updated more often, bmTuned or DiagonalOBDII?

bmTuned ships an update every 7 months, and DiagonalOBDII every 2 weeks. Most recently, bmTuned was updated on September 14, 2026 and DiagonalOBDII on October 5, 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.*