Comparison

PerfExpert vs JB4 Mobile

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

Head to head
About

PerfExpert

Transform your smartphone into a powerful onboard dyno to measure your car's engine power and torque with high accuracy. Verify tuning, remaps, and upgrades with detailed reports and interactive charts. No external sensors or car connection required.

Highlights
  • Engine power and torque measurement
  • 0-60 mph and 0-100 km/h acceleration times
  • Quarter mile and 400m times
  • Detailed reports with interactive charts
  • Correction standards (DIN, SAE, ISO, JIS, CEE)
  • Customizable units
  • Export results as data files or images
Features
Read full description

Know your car's true performance. Turn your smartphone into a professional dyno. Measure the real horsepower and torque of your engine — within 2% of a chassis dynamometer — and time your car's acceleration. No OBD adapter, no cables, no expensive dyno sessions. Just mount your phone, accelerate, and get instant results. Test and compare performance upgrades. Whether you're verifying an ECU remap, testing a new exhaust, or tracking the effect of a chiptuning session, PerfExpert gives you objective, independent data you can trust. HOW IT WORKS 1. Create your car profile Enter your vehicle's weight, tire sizes, and gear ratios. Not sure about a spec? The app guides you through every step. 2. Mount your phone & accelerate Secure your phone in the car — no connection needed. Find a flat, straight road. Accelerate in one gear from low RPM to redline. That's it. 3. Get instant results Power and torque curves appear immediately, just like on a real chassis dynamometer. Compare runs, track your modifications, and share results. MEASUREMENT MODES Dyno — Full power & torque curves vs. engine RPM. Advanced drivetrain loss model, rev limiter detection, and correction standards (DIN, SAE, JIS, CEE, ISO). Results as detailed as a professional chassis dyno. Timed Run — Measure acceleration from a standing start. Speed intervals: 0-100, 100-200, 80-180, 60-160 km/h — 0-60, 60-120, 50-110, 40-100 mph. Distance: quarter mile, eighth mile (with trap speed), 60 ft. Max speed and peak acceleration on every run. KEY FEATURES - 2% accuracy compared to professional chassis dynamometers - No OBD adapter or connection to your car required - Works with your phone's built-in sensors - External GPS available as an in-app purchase for pro-level precision with a compatible device (RaceBox Mini, Mini S, Micro): rolling start dyno, free phone mounting - Power correction norms: DIN, SAE, JIS, CEE, ISO — using real-time atmospheric pressure, temperature, and humidity - Interactive charts: pinch to zoom, tap for exact values - Export results as PNG image or shareable web link - Custom units: HP, CV, kW for power — Nm, ft-lb, mkg for torque — km/h, mph for speed - Works on phones and tablets PERFEXPERT PRO (optional subscription) - Custom logo on your results - Cloud backup of your results - CSV data export WHO USES PERFEXPERT? - Car enthusiasts who want to know their real HP and torque - Tuners and mechanics verifying ECU remaps, chiptuning, intake, exhaust, or turbo upgrades - Owners comparing before/after results of any modification - Drivers timing their 0-60 mph or 0-100 km/h acceleration - Anyone curious about their car's true performance IMPORTANT NOTES - Dyno mode requires a manual gearbox or an automatic with manual/sequential mode - For best results, use a flat, straight, horizontal road with no traffic - External GPS (in-app purchase) unlocks additional features with a compatible device (RaceBox Mini, Mini S, Micro): more reliable results, rolling start dyno (no need to stop before measuring), and free phone orientation Sample dyno and acceleration reports: https://app.perfexpert-app.com/results/featured FAQ and support: https://www.perfexpert-app.com/faq Join the PerfExpert community: https://www.facebook.com/groups/perfexpert/ Privacy Policy: https://www.perfexpert-app.com/privacy-policy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

JB4 Mobile

This app acts as a mobile data logger and display for vehicles equipped with a JB4 tuner. It allows users to monitor and log various engine parameters, view data in real-time, and adjust settings for performance tuning.

Highlights
  • Live gauge monitoring
  • Data logging and graphing
  • User adjustable settings
  • WMI settings modification
  • On-the-fly map switching
  • Code reading and deletion
Features
Read full description

The brand new JB4 Mobile application is finally ready for public release and has lots of great new features including: *Gauge theme customizations *Built-in raw CSV data viewer *Revamped User Adj./WMI data editors *New modern UI completely rewritten from the ground up *More seamless integration with our backend servers JB4 Connect Kit Users: 1) Install the Connect Kit per the installation guide for your vehicle 2) Create your account/sign in with this app 3) Ensure JB4 Mobile has all requested permissions 4) Tap the Connect button in JB4 Mobile About The App: JB4 Mobile is a mobile data logger and display for use with the JB4 tuner from Burger Motorsports. JB4 Mobile allows you to monitor and log multiple parameters from your JB4 equipped car. Parameters such as boost, rpm, fuel trims, air/fuel ratios, ignition advance and much more are available. Current Features: Live gauges Data logging Data graphing Log export via email Code reading/deletion Modify User Adj. (boost, fuel, etc.) settings Modify WMI settings Switch maps on the fly Auto WOT logging JB4 Firmware Updating JB4 ® is a registered trademark of Burger Motorsports Inc ® and is used with written permission.

Screenshots

PerfExpert4 screens
JB4 Mobile4 screens

Verdict

The call

The clearest difference is price: PerfExpert at $8.99 against JB4 Mobile's $27.99. PerfExpert also leads on review sentiment (63% vs 52%). JB4 Mobile's advantage is in-app purchases (none vs 8) and ratings volume (239 vs 12). On rating, 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

PerfExpert costs $8.99 and JB4 Mobile $27.99 up front. PerfExpert sells 8 in-app purchases, starting at $11.99 per month. JB4 Mobile asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 3.7 for PerfExpert against 3.8 for JB4 Mobile. That said, the two scores are not equally well evidenced: JB4 Mobile has 239 ratings behind it against 12, so its average is the more settled of the two. Written reviews are what separate them: 63% of PerfExpert's written reviews are positive against 52% of JB4 Mobile's.

UpkeepUpdate frequency

PerfExpert ships an update every 2 months, JB4 Mobile every 3 months. Both last shipped on November 1, 2026.

Scorecard6 real differences · 5 level
PerfExpert versus JB4 Mobile: the parameters behind the verdict, then further details
ParameterPerfExpertJB4 Mobile
Price$8.99 — better$27.99
Rating3.7 (12 ratings)3.8 (239 ratings) — better
Positive reviews63.4% of reviews — better52.4% of reviews
Number of ratings12239 — better
Update frequencyEvery 2 months — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
Best chart rank—#4 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.0 — better15.1
Further details — not scored
Size30 MB24 MB
Age rating4+4+
DeveloperClaude JOSEPH ANGELIQUEDmac Mobile Developments, LLC

Customer experience

PerfExpert

All ratings12 ratings
Positive66.7%
Neutral8.3%
Negative25.0%
Written reviews101 reviews
Positive63.4%
Neutral6.9%
Negative29.7%

JB4 Mobile

All ratings239 ratings
Positive66.9%
Neutral12.1%
Negative20.9%
Written reviews145 reviews
Positive52.4%
Neutral13.1%
Negative34.5%

Bugs and requests

PerfExpert

Not enough reviews yet to summarise bugs or requests.

JB4 Mobile

Reported bugs

5 issues
  • App crashes
  • Can't connect to server
  • Mirrored/inverted display
  • Compatibility issues with new iOS versions
  • Trouble logging in

Requested features

5 requests
  • Add CarPlay support
  • Allow customizing map names
  • Add more gauge styling options
  • Improve UI and layout
  • Integrate with Apple Carplay

In-app purchases

8 purchases

PerfExpert

Subscriptions4
  • PerfExpert Pro$11.991 Month
  • PerfExpert Pro Max$24.991 Month
  • PerfExpert Pro$89.991 Year
Show 1 more
  • PerfExpert Pro Max$199.991 Year
One-time4
  • 1 Extra Car Profile$3.99
  • 3 Extra Car Profiles$9.99
  • 5 Extra Car Profiles$14.99
Show 1 more
  • External GPS Unlock$22.99
None

JB4 Mobile

No in-app purchases

Questions

Is PerfExpert free?
PerfExpert costs $8.99, and also offers in-app purchases.
Is JB4 Mobile free?
JB4 Mobile costs $27.99, with no in-app purchases.
Which has better reviews, PerfExpert or JB4 Mobile?
JB4 Mobile is rated higher. PerfExpert averages 3.7 out of 5 from 12 ratings, while JB4 Mobile averages 3.8 from 239 ratings.
Do PerfExpert or JB4 Mobile have ads?
Neither PerfExpert nor JB4 Mobile shows ads.
Which is updated more often, PerfExpert or JB4 Mobile?
PerfExpert ships an update every 2 months, and JB4 Mobile every 3 months. Most recently, PerfExpert was updated on November 1, 2026 and JB4 Mobile on November 1, 2026.

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