WattGrowl: EV Car Engine Sound

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In-app purchases

About this app

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

DRIVE IT LIVE
Mount your phone, 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.
Live Drive is the premium part of WattGrowl: unlock it with a yearly subscription or a one-time lifetime purchase. Everything else is free.

37 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 Workshop.

GEARBOXES AND DRIVING MODES
Manual, dual-clutch, automatic, sequential, CVT or single-speed. Shift from 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, DCT upshift "brap" and limiter bangs are all there.

SOUNDS RIGHT IN YOUR CAR
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 ducking balances the engine against your playlist. A hearing-safety cap limits the volume on headphones.

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 Workshop: 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 is uploaded.
• Works with any EV and any car stereo — connect your phone over Bluetooth, a cable or USB.

Built by an EV driver who missed the growl.

What’s new

First test release of WattGrowl.
• 37 synthesized engines, Simulator and Garage rev (free)
• Live Drive (premium): live engine sound from your phone's motion sensors and GPS while you drive
• Per-engine pops & bangs, throttle pad at a standstill
• Stops when the car audio disconnects, restarts when the same car reconnects
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