# ASE Mechanic Prep Exam: A1-A8 — Gear Ratio & OBD-II Tools

> Gear Ratio & OBD-II Tools (iPhone/iPad app by Deeun Inc..)

- Source: https://appshunter.io/ios/app/ase-mechanic-prep-exam-a1-a8/id6759874293 (this page in markdown: same URL + `.md`)
- Developer: [Deeun Inc.](https://appshunter.io/developer/1691824695)
- Category: Education, Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 4 MB
- Languages: American English
- Released: 2026-03-01
- Data updated: 2026-06-09
- User reviews in markdown: https://appshunter.io/ios/app/ase-mechanic-prep-exam-a1-a8/id6759874293/reviews.md

## What is ASE Mechanic Prep Exam?

ASE MECHANIC PREP: YOUR COMPLETE A1-A8 CERTIFICATION TOOLKIT

The tools you use in the shop. The questions you see on the test. One app. 

GEAR RATIO CALCULATOR

Figure out final drive ratios, speedometer correction, and RPM at any speed.

Enter your ring and pinion teeth. Select your transmission gear. Input your tire size.

The app calculates:
- Final drive ratio
- Effective gear ratio in any gear
- RPM at any speed
- Speed at any RPM
- Speedometer correction for tire changes

Save multiple vehicle setups. Compare stock versus modified. Know exactly what happens before you swap gears.

COMPRESSION RATIO CALCULATOR

Building an engine? Need to verify specs? Calculate compression ratio from:

- Bore and stroke
- Combustion chamber volume
- Head gasket thickness
- Piston dome or dish volume
- Deck clearance

Get accurate compression ratio and fuel octane recommendations. No more guessing if you need premium.

OBD-II CODE REFERENCE

Over 500 diagnostic trouble codes with:
- Plain English descriptions
- Common causes
- Diagnostic steps
- Related codes

Search by code or description. Works offline. The code database every mechanic needs.

TIRE SIZE CALCULATOR

Compare tire sizes instantly:
- Diameter difference
- Speedometer error
- Revolutions per mile
- Width and sidewall changes

Know if that tire upgrade will fit before you buy.

1000+ PRACTICE QUESTIONS

All eight ASE A-series tests:

A1 - Engine Repair
- Compression and leak-down testing
- Valve train service
- Timing belt and chain
- Cooling and lubrication systems

A2 - Automatic Transmission
- Fluid diagnosis
- Pressure testing
- Torque converter operation
- Electronic controls

A3 - Manual Drivetrain
- Clutch service
- Synchronizer operation
- Differential setup
- CV and U-joint service

A4 - Suspension and Steering
- Alignment angles
- Power steering diagnosis
- Ball joint and bushing inspection
- Electronic steering systems

A5 - Brakes
- Hydraulic system diagnosis
- ABS operation
- Rotor measurement
- Pad and shoe service

A6 - Electrical Systems
- Voltage drop testing
- Parasitic draw diagnosis
- Wiring diagram reading
- CAN bus communication

A7 - Heating and Air Conditioning
- Refrigerant handling
- System diagnosis
- Component testing
- EPA regulations

A8 - Engine Performance
- Scan tool interpretation
- Fuel trim analysis
- Ignition diagnosis
- Emissions systems

BUILT FOR THE SHOP

Dark theme for working under vehicles.
High contrast for greasy screens.
Large buttons for dirty hands.
Works offline.

WHO NEEDS THIS APP

- Automotive technology students
- Working mechanics seeking certification
- Technicians recertifying (every 5 years)
- Service advisors
- Dealership employees
- DIY enthusiasts

FREE TO START

5 questions per day free. Calculators in limited mode. Upgrade for unlimited access.

PRO - LIFETIME ACCESS

- Unlimited practice questions (all 8 tests)
- Full gear ratio calculator
- Full compression ratio calculator
- Complete OBD-II code database
- Tire size calculator
- Reference library

PASS YOUR ASE. ADVANCE YOUR CAREER.

ASE certification is required at most dealerships and respected at every shop. With recertification every 5 years, this app pays for itself again and again.

This app is for educational purposes and reference only. Always follow manufacturer specifications and shop procedures for actual repair work.

Privacy Policy: https://www.voltexam.com/privacy
Terms & Conditions: https://www.voltexam.com/terms
Terms of Service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| ASE Mechanic Exam Prep Pro Monthly | $6.99 | per month |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro - Lifetime Access | $17.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-03-02

No release notes.

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All apps by Deeun Inc.: https://appshunter.io/developer/1691824695

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