E85 Calculator vs eFlexApp
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
E85 Calculator
This application helps performance enthusiasts and flex-fuel vehicle owners precisely calculate the amounts of E85 and gasoline needed for specific ethanol percentages or octane ratings. It offers both simple and advanced modes for fuel mixing calculations, supporting metric and imperial units.
- Calculate E85 and gasoline amounts
- Target specific ethanol percentages
- Calculate by desired octane rating
- Metric and imperial unit support
- Real-time calculations
- Easy and advanced modes
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E85 Calculator is your essential tool for precision fuel mixing, designed for performance enthusiasts and flex-fuel vehicle owners. KEY FEATURES: - Calculate exact amounts of E85 and gasoline needed - Target specific ethanol percentages (E30, E50, E70, E85) - Calculate by desired octane rating - Support for both metric (liters) and imperial (gallons) units - Real-time calculations with instant updates - Easy and advanced modes for different user needs EASY MODE: - Quick presets for common ethanol targets - Simple tank size selection - Intuitive slider controls for current fuel level - Basic inputs for everyday use ADVANCED MODE: - Precise control over fuel properties - Custom octane ratings input - Detailed ethanol content adjustment - Advanced fuel mixing calculations Perfect for: - Flex-fuel vehicle owners - Performance car enthusiasts - Race car tuners - Anyone mixing E85 with regular gas Get accurate calculations every time and achieve the perfect fuel blend for your vehicle's needs. Whether you're targeting a specific ethanol percentage or octane rating, E85 Calculator provides the precise measurements you need. Safe, simple, and accurate - take the guesswork out of fuel mixing with E85 Calculator.
eFlexApp
Monitor your eFlexFuel device in real-time, with features varying by device version. Adjust settings like language, temperature units, and theme. Track ethanol content, engine temperature, and more, depending on your specific eFlexFuel model.
- Real-time device monitoring
- Adjustable settings (language, temp, theme)
- Ethanol content tracking
- Engine temperature monitoring
- Device status checks
- Bluetooth connectivity
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With eFlexApp you can monitor your eFlexFuel device in real time. eFlexApp recognizes your eFlexFuel device version and offers different features with each product. The app also enables adjusting of eFlexPlus and eFlexPro devices. Change language (English, French, Finnish), temperature unit (°F/°C) and theme (light/dark). eFlexEco, eFlexBlue and eFlexFuel MONITOR: ethanol content, duty cycle, fuel temperature, ambient engine temperature, injector activity & cold enrichment, (engine RPM in eFlexEco Firmware 11.0+) CHECK: device status eFlexPlus Direct, eFlexBlue Direct MONITOR: ethanol content, engine RPM, duty cycle, fuel temperature, ambient engine temperature, injector activity & cold enrichment CHECK: device status eFlexPlus and eFlexMoto Plus MONITOR: ethanol content, engine RPM, duty cycle, fuel temperature, ambient engine temperature, injector activity & cold enrichment ADJUST: RPM based enrichment with driving mode selection (save a custom driving mode setting created with eFlexTuner software) & cold enrichment (save a custom setting created with eFlexTuner software) CHECK: device status, startup information eFlexPro and eFlexMoto Pro MONITOR: ethanol content, engine RPM, duty cycle, fuel temperature, ambient engine temperature, injector activity & cold enrichment ADJUST: RPM based enrichment with driving mode selection (save up to three custom driving mode settings created with eFlexTuner software) & cold enrichment (save a custom setting created with eFlexTuner software) CHECK: device status, startup information eFlexApp communicates with your eFlexFuel device via Bluetooth. Permission to use Bluetooth is required. Please contact support@eflexfuel.com if you have any feedback! Developed by StepOne Tech Ltd
Screenshots
Verdict
The clearest difference is rating: eFlexApp at 3.2 against E85 Calculator's 1.0. eFlexApp also leads on update cadence (monthly vs every 29 months) and ratings volume (10 vs 2). E85 Calculator's advantage is iOS requirement (16.0 vs 26.6). On price, review sentiment, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
eFlexApp holds the better App Store score, 3.2 against 1.0. That said, the two scores are not equally well evidenced: eFlexApp has 10 ratings behind it against 2, so its average is the more settled of the two. Written reviews split almost evenly too, at 25% and 25% positive.
E85 Calculator ships an update every 29 months, eFlexApp monthly. The most recent releases landed on October 10, 2026 and October 17, 2026 respectively.
| Parameter | E85 Calculator | eFlexApp |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (2 ratings) | 3.2 (10 ratings) — better |
| Positive reviews | 25.0% of reviews | 25.0% of reviews |
| Number of ratings | 2 | 10 — better |
| Update frequency | Every 29 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad — better | iPhone |
| Requires iOS | 16.0 — better | 26.6 |
| Further details — not scored | ||
| Size | 3 MB | 53 MB |
| Age rating | 4+ | 4+ |
| Developer | Sheharyar Irfan | StepOne Tech Ltd |
Customer experience
E85 Calculator
eFlexApp
In-app purchases
E85 Calculator
No in-app purchases
eFlexApp
No in-app purchases







