Comparison

TopGuru vs Engine Displacement Calc

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

TopGuru

Transform your phone or tablet into a powerful vehicle diagnostic tool via Bluetooth. Access full system diagnosis, OBDII functions, bi-directional controls, and essential maintenance services for a wide range of car brands. Generate detailed diagnostic reports for efficient troubleshooting.

Highlights
  • Full System Diagnosis
  • Full OBD2 Functions
  • Bi-directional Control
  • 8 Special Maintenance Functions
  • AutoVIN Vehicle Identification
  • Diagnostic Report Generation
  • Wireless Bluetooth 5.0 Connection
Features
Read full description

Easily link the app with your Phone or Tablet using Bluetooth, transforming your devices into a smart and high-powered diagnostic tool! Packed with essential features like complete OBDII functionality, all system diagnosis, Bi-Directional controls, AutoVIN, automatic diagnostic reports, and more, this Bluetooth OBDII scan tool is a must-have for technicians. Its versatility shines through with eight maintenance service functions and coverage for over 60 vehicle brands, making the product a portable and adaptable auto scanner. Main Features: 1. Full System Diagnosis: Covers Engine, Transmission, Airbag, ABS, ESP, TPMS, Immobilizer, Gateway, Steering, Radio, Air Conditioning, and more. 2. Full OBD2 Functions: works as an OBD2 code reader and performs all 10 modes of OBD2 testing free for life. 3. Bi-directional Control: Easily locate issues with active tests. 4. 8 Special Functions: Perform Oil Reset, Throttle Adaptation, EPB Reset, BMS Reset, and more. 5. Repair Data Library: Includes DTC Repair Guide, Technical Service Bulletin, DLC Location, Warning Light Library. 6. AutoVIN: Enables automatic vehicle identification for quick diagnosis. 7. Wireless Connection: Utilizes Bluetooth 5.0 with a range of 33 feet/10m. 8. Graphs, Values, and Dashboard-like Data Display: Ensures easy interpretation of information. 9. Generate Diagnostic Reports: Obtain detailed reports for Systems, Fault Codes, or Data Streams. 10. Pro version features 13 reset functions and IMMO capability. Terms of Use (EULA): https://plat.topdon.com/topdon-plat/out-user/baseinfo/template/getHtmlContentById?softCode=TopScan_DisplaySW_iOS&language=7&type=25

About

Engine Displacement Calc

Features
Read full description

Need to know the exact displacement of an engine build before ordering parts? Whether you are verifying a crate motor, sizing a swap, or checking class compliance, this app calculates total engine displacement from bore, stroke, and cylinder count in seconds. Supports metric (mm) and imperial (inches). Shows total volume in cc, liters, and cubic inches. Includes bore/stroke ratio analysis with square, oversquare, and undersquare classification. FEATURES: - Enter bore diameter, stroke length, and number of cylinders - Instant per-cylinder and total displacement - Output in cc, liters, and cubic inches simultaneously - Bore/stroke ratio with automatic classification - Metric and imperial unit toggle - Works completely offline Perfect for engine builders, mechanics, race teams, and automotive enthusiasts who need accurate displacement figures on the spot.

Screenshots

TopGuru4 screens
Engine Displacement Calc3 screens

Verdict

The call

The clearest difference is price: TopGuru at Free against Engine Displacement Calc's $4.99. TopGuru also leads on chart position (#162 vs unranked) and iOS requirement (15.0 vs 17.0). Engine Displacement Calc's advantage is in-app purchases (none vs 30). On update cadence, ads and device support 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

CostPrice · In-app purchases · Ads · Monetization

TopGuru is free to download; Engine Displacement Calc costs $4.99 up front. TopGuru sells 21 in-app purchases, starting at $9.99 per month. Engine Displacement Calc asks for nothing beyond the download.

UpkeepUpdate frequency

TopGuru ships an update every 3 weeks, Engine Displacement Calc every 6 weeks. The most recent releases landed on October 27, 2026 and October 18, 2026 respectively.

Scorecard4 real differences · 7 level
TopGuru versus Engine Displacement Calc: the parameters behind the verdict, then further details
ParameterTopGuruEngine Displacement Calc
PriceFree — better$4.99
Rating3.5 (412 ratings) — better—
Positive reviews29.3% of reviews—
Number of ratings412 — better—
Update frequencyEvery 3 weeks — betterEvery 6 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
Best chart rank#162 — better—
DevicesiPhone, iPodiPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size2.2 GB1 MB
Age rating4+4+
DeveloperHK TOPDON TECHNOLOGY Co., LIMITEDShanghai Sheyuan Network Technology Co., Ltd.

Bugs and requests

TopGuru

Reported bugs

3 issues
  • Incompatibility with certain vehicle models
  • Login and account issues
  • Unreliable Bluetooth connectivity

Requested features

3 requests
  • iPad optimization and full-screen support
  • Expanded vehicle coverage, especially for motorcycles
  • Ability to save and export diagnostic data

Engine Displacement Calc

Not enough reviews yet to summarise bugs or requests.

In-app purchases

21 purchases

TopGuru

Subscriptions5
  • Monthly Auto-renewal$9.991 Month
  • Monthly Auto-renewal$19.001 Month
  • Quarterly Auto-renewal$24.993 Months
Show 2 more
  • Annual Auto-renewal$49.991 Year
  • Annual Auto-renewal$99.001 Year
One-time16
  • Renault Gateway 1-Token$11.99
  • Diag Bundle Renewal3 variants$49.99
  • TopGuru Diagnostic Bundle$49.99
Show 13 more
  • TopGuru IMMO Bundle$49.99
  • Renewal Bundle4 variants$99.00
  • TopScan Pro Renewal Bundle3 variants$99.00
  • Harley Moto Software$99.99
  • Harley Moto Software Renewal$99.99
  • Moto Diag Bundle Renewal-Moto$99.99
  • Moto Diag Bundle$99.99
  • Moto Diag Bundle Renewal$99.99
  • 22 Special Functions Bundle2 variants$129.99
  • Renault Gateway 10 Tokens$129.99
  • Renault Gateway 5 Tokens$147.99
  • 17 Special Functions Bundle2 variants$179.00
  • FCA Gateway 1-year (EU only)$229.99
None

Engine Displacement Calc

No in-app purchases

Questions

Is TopGuru free?
TopGuru is free to download, with in-app purchases available.
Is Engine Displacement Calc free?
Engine Displacement Calc costs $4.99, with no in-app purchases.
Do TopGuru or Engine Displacement Calc have ads?
Neither TopGuru nor Engine Displacement Calc shows ads.
Which is updated more often, TopGuru or Engine Displacement Calc?
TopGuru ships an update every 3 weeks, and Engine Displacement Calc every 6 weeks. Most recently, TopGuru was updated on October 27, 2026 and Engine Displacement Calc on October 18, 2026.

Other comparisons