Comparison

Compression Calculator vs PowerVision 4

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

Head to head
About

Compression Calculator

Calculate engine compression, displacement, and piston speed using specific Honda engine parameters. Select engine components to get precise calculations for your automotive needs.

Highlights
  • Engine compression calculation
  • Displacement calculation
  • Piston speed calculation
  • Honda B, D, H/F, K-Series engine support
  • Component selection for custom calculations
Features
Read full description

Engine Compression Calculator which contains B-, D-, H/F- and K-Series Honda™ Engine parameters. Select your engine components and calculate your engine compression, displacement, pistons speed...etc. The trademark "Honda" and any other product names, service names or logos of Honda used, quoted and/or referenced in this app are trademarks or registered trademarks of Honda or any of its affiliates. Other product names and/or company names used in the app may be protected as their trademarks and/or trade names.

About

PowerVision 4

Control your motorcycle's engine performance directly from your iPhone. Access hundreds of pre-loaded engine tunes or create custom ones. Easily flash tunes to your bike's ECU, monitor real-time engine data, and manage diagnostic trouble codes.

Highlights
  • Flash tunes to ECU
  • Access vast tune database
  • Record real-time engine data
  • Read/clear diagnostic codes
  • Remote tuning optimization
  • Autotune modes
  • Active tests for diagnostics
Features
Read full description

Power Vision 4 from Dynojet Research Inc. combined with your iPhone puts you in control of your bike’s engine. Gain access to hundreds of different tunes for various aftermarket components and easily flash any of them to you bike’s ECU. Unbelievably quick and easy to use; make more power and torque with the push of a button. Advanced users can edit hundreds of individual engine parameters to build a tune that’s dialed in for their unique setup using Dynojet’s integrated cloud tune delivery system. With the PV4 App and our pocket-sized PV4 device you can: • Flash tunes to your ECU – no setup required, just create an account, select your tune, flash, and ride the ultimate ride. • Access to vast database of pre-loaded tunes for different configurations – no custom tuning required. • Easily download and manage pre-loaded and custom tunes. • Record real-time engine data and review in WinPEP 8 Data Center. • Read, review, clear, and share diagnostic trouble codes (DTC’s) with built-in descriptions. • Flash an unlimited number of bikes with one device.* • Use licenses from your Power Vision Classic with your Power Vision 4. • Return to stock at any time – your original, factory tune is safely backed up on the cloud and on your phone. • Optimized for remote-tuning. – Easily ride, record, and share data logs with your tuner for trouble-free custom tuning without a dynamometer. • Keep your ECU – The Power Vision 4 reprograms your bike without having to remove or mail-in the ECU. Just plug into the diagnostic connector and flash, it’s really that easy. • Autotune - Choose from three different Autotune modes to dial your HD motorcycle in the way that fits you best. • Dynamometer Compatible - Plug your PV4 directly into your Dynojet Dynamometer to view channels, flash, read diagnostic information, read RPM via OBD, and load control without an inductive pickup. • Flashes on HD motorcycles as fast as 12.75 seconds (select models) • Active Tests help diagnose problems on your HD - cycle the fuel pump, indicators, water pump, and many other components when troubleshooting engine or electrical issues. • Diagnostic Routines allow you to bleed the ABS system at home World class, US-based customer service from our team of motorcycle enthusiasts is also available to suggest the best tune, review data recordings, or assist in troubleshooting. Your ultimate ride awaits with Power Vision 4 – download the app and see how easy tuning can be! * First bike license included with purchase of Power Vision 4 device. Requires purchase of license for each additional bike DISCLAIMER: Not legal for sale or use in California

Screenshots

Compression Calculator2 screens
PowerVision 44 screens

Verdict

The call

The clearest difference is review sentiment: PowerVision 4 at 78% against Compression Calculator's 0%. PowerVision 4 also leads on rating (4.9 vs 3.0) and ratings volume (312 vs 3). Compression Calculator's advantage is in-app purchases (none vs 8) and update cadence (every 9 days vs monthly). On price, 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

Both are free to download. PowerVision 4 sells 8 one-off in-app purchases. Compression Calculator asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

PowerVision 4 holds the better App Store score, 4.9 against 3.0. That said, the two scores are not equally well evidenced: PowerVision 4 has 312 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 0% of Compression Calculator's written reviews are positive against 78% of PowerVision 4's.

UpkeepUpdate frequency

Compression Calculator ships an update every 9 days, PowerVision 4 monthly. The most recent releases landed on September 30, 2026 and October 16, 2026 respectively.

Scorecard7 real differences · 3 level
Compression Calculator versus PowerVision 4: the parameters behind the verdict, then further details
ParameterCompression CalculatorPowerVision 4
PriceFreeFree
Rating3.0 (3 ratings)4.9 (312 ratings) — better
Positive reviews0.0% of reviews77.9% of reviews — better
Number of ratings3312 — better
Update frequencyEvery 9 days — betterMonthly
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS11.4 — better15.0
Further details — not scored
Size10 MB104 MB
Age rating4+4+
DeveloperPeter LinszterDynojet

Customer experience

Compression Calculator

All ratings3 ratings
Positive33.3%
Neutral33.3%
Negative33.3%
Written reviews2 reviews
Positive0.0%
Neutral50.0%
Negative50.0%

PowerVision 4

All ratings312 ratings
Positive98.1%
Neutral1.0%
Negative1.0%
Written reviews163 reviews
Positive77.9%
Neutral8.0%
Negative14.1%

Bugs and requests

Compression Calculator

Not enough reviews yet to summarise bugs or requests.

PowerVision 4

Reported bugs

4 issues
  • App crashes when using diagnostic functions
  • Bluetooth disconnects during tuning process
  • Sensor readings not updating correctly
  • Tune flashing fails intermittently

Requested features

5 requests
  • Add more pre-loaded tune options
  • Implement an auto-tune feature
  • Improve data logging and cloud integration
  • Expand support for wider range of bikes
  • Enhance live sensor data display

In-app purchases

None

Compression Calculator

No in-app purchases

8 purchases

PowerVision 4

One-time8
  • Universal Token$10.00
  • Universal Token (3x)$30.00
  • Universal Token (5x)$50.00
Show 5 more
  • Universal Token (10x)$100.00
  • Universal Token (15x)$150.00
  • Universal Token (20x)$200.00
  • Universal Token (25x)$250.00
  • Universal Token (30x)$300.00

Questions

Is Compression Calculator free?
Compression Calculator is free to download, with no in-app purchases.
Is PowerVision 4 free?
PowerVision 4 is free to download, with in-app purchases available.
Which has better reviews, Compression Calculator or PowerVision 4?
PowerVision 4 is rated higher. Compression Calculator averages 3.0 out of 5 from 3 ratings, while PowerVision 4 averages 4.9 from 312 ratings.
Do Compression Calculator or PowerVision 4 have ads?
Neither Compression Calculator nor PowerVision 4 shows ads.
Which is updated more often, Compression Calculator or PowerVision 4?
Compression Calculator ships an update every 9 days, and PowerVision 4 monthly. Most recently, Compression Calculator was updated on September 30, 2026 and PowerVision 4 on October 16, 2026.

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