WattGrowl: EV Car Engine Sound

Give any car the voice of a combustion engine: V8 growl, turbo whistle and pops & bangs, synthesized live on your iPhone. New: tunnel echo and 17-second rev videos.

Miss the sound of a real engine? WattGrowl gives your car — electric, hybrid or gas — the voice of a combustion engine — synthesized live on your iPhone and played through your car's speakers over Bluetooth, CarPlay or a cable. No hardware, no OBD dongle, no wiring.

DRIVE IT LIVE Mount your iPhone, pick an engine and drive. WattGrowl reads the phone's motion sensors and GPS, works out how hard you are accelerating, braking or coasting, and plays the matching engine note in real time: idle, pull, lift-off crackle, gear changes, turbo spool and blow-off. It calibrates itself to the way your phone is mounted and keeps the sound steady over bumps and rough roads; a phone-holder guide shows the best way to mount it. Live Drive is the premium part of WattGrowl: subscribe yearly, or unlock it for life with a one-time purchase. Everything else is free.

38 ENGINES, ALL SYNTHESIZED Small-block and big-block V8s, a flat-plane screamer, twin-turbo straight-sixes, a rally boxer, a hot-hatch four, high-revving V10s and V12s, a quad-turbo W16, twin-rotor and quad-rotor rotaries, diesels and superbikes. Every engine is modeled, not looped: firing order, exhaust pipes, muffler, turbo, supercharger and limiter all shape the sound. Build your own in the Engine Builder.

GEARBOXES AND DRIVING MODES Manual, dual-clutch, automatic, sequential, CVT or single-speed. Shift with on-screen paddles or your steering-wheel media buttons. Eco to Track drive modes change how the engine responds.

POPS, BANGS AND CRACKLE Lift off and hear overrun crackle shaped by that engine's own exhaust. Tap POP for a backfire at a standstill. Rally anti-lag, the dual-clutch upshift "brap" and limiter bangs are all there.

SHARE YOUR BUILD Record a 17-second rev and share it as a video, or share your engine's build sheet with its power and torque curves.

SOUNDS RIGHT IN YOUR CAR Pick Standard or Enhanced sound quality, and tap TUNNEL for a tunnel's echo. The front/rear sound stage puts the intake up front and the exhaust behind you. Automatic latency compensation keeps the sound in step with the pedal over Bluetooth. Music balance keeps the engine and your playlist together. A hearing-safety cap limits how loud the engine can play.

MADE FOR iPHONE • The engine keeps running with the screen off; a Live Activity on the Lock Screen shows it, with Mute and Stop • "Start the engine" in Shortcuts: start it automatically when your car or CarPlay connects • In 23 languages

ALSO IN THE APP • Free: simulator with on-screen throttle and brake — try any engine anywhere • Free: garage rev mode — blip the throttle while parked • Live Drive: throttle pad at traffic lights — rev at a standstill, back to gears when you move off • 0–60 mph, 0–100 km/h and quarter-mile timers, trip statistics • Drive recordings to review and share • Engine Builder: edit every synthesis parameter, save your own engines • Dark, glanceable dashboard with classic, modern, race and retro themes

GOOD TO KNOW • The sound plays inside the car for you, the driver. It is not a pedestrian warning system and does not replace your car's AVAS. • Keep your eyes on the road: WattGrowl is designed to run hands-free once started. Set it up before you drive. • Location is used only to measure speed for the engine sound; nothing leaves your phone. • Works with any car and any car stereo: pick your car type, or enter its horsepower and weight. Connect over Bluetooth, CarPlay or a cable.

LIVE DRIVE SUBSCRIPTION The yearly plan is charged to your Apple Account when you confirm the purchase, or when the free trial ends if you are eligible for one. It renews automatically unless you cancel it at least 24 hours before the end of the current period. Manage or cancel it in your Apple Account settings. The lifetime unlock is a one-time purchase. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://wattgrowl.com/privacy/

Built by an EV driver who missed the growl.