# E vs Part 117

The clearest difference is price: E at Free against Part 117's $4.99. E also leads on iOS requirement (16.0 vs 18.0). Part 117's advantage is update cadence (daily vs every 4 months) and chart position (#187 vs unranked). On ads, in-app purchases and device support there is nothing between them.

E is free to download; Part 117 costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

E ships an update every 4 months, Part 117 daily. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | E | Part 117 |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | **[3.9 (24 ratings)](https://appshunter.io/ios/app/e-tuner-4/id1579096205/reviews)** | — |
| Number of ratings | **24** | — |
| Positive reviews | 46.2% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Daily** |
| Monetization | Free | — |
| Best chart rank | — | **#187** |
| Size | 51 MB | 24 MB |
| Requires iOS | **16.0** | 18.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Edelbrock Corp](https://appshunter.io/developer/1579096297) | [Perry Tanner](https://appshunter.io/developer/6780700925) |

## What reviewers say

### E

[App page](https://appshunter.io/ios/app/e-tuner-4/id1579096205)

This app connects wirelessly to an EFI system, allowing users to monitor engine data and adjust various settings like air-fuel ratios and ignition timing. It offers a setup wizard for initial calibration and advanced tuning options for performance optimization.

**Highlights:** Bluetooth ECU communication, Live tuning of ECU settings, Real-time engine and sensor data monitoring, Setup Wizard for base calibration, Advanced tuning functions, Diagnostic troubleshooting page, Vivid gauge displays

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

**In-app purchases:** none


### Part 117

[App page](https://appshunter.io/ios/app/part-117-fdp-tracker-and-guide/id6780700923)

**Currently charting:** #187 Top Paid · Utilities (US App Store)

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

**In-app purchases:** none


## Frequently asked questions

### Is E free?

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

### Is Part 117 free?

Part 117 costs $4.99, with no in-app purchases.

### Do E or Part 117 have ads?

Neither E nor Part 117 shows ads.

### Which is updated more often, E or Part 117?

E ships an update every 4 months, and Part 117 daily. Most recently, E was updated on November 3, 2026 and Part 117 on October 31, 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.*