engine sound simulator | hear your cruise RPM: gear ratios, axle, tire size, regear A/B

Engine sound simulator in the browser: enter your gear ratios, axle ratio and tire size, pick a speed, and hear your engine at the real RPM in every gear.

Example of the result this page gives you

How it works

Enter your details in the free version below.
See your result right away on this page.
Need more? The full version adds what is listed under "What you get".

Published 2026-11-12 · ReadyStack

Example (made-up): an 8-speed with a 0.67 top gear, a 3.21 axle and 255/75R17 tires (32.06 in) turns 70 mph × 3.21 × 0.67 × 336.13 ÷ 32.06 = 1,578 rpm. Put 315/70R17 tires on (34.36 in) and keep the 3.21: it drops to 1,473 rpm and the speedometer reads 70 while you really do 75 mph. Regear to 4.10 and it climbs to 1,881 rpm. Hear all three on a V8 below before you pay for gears or tires.

The app simulators give you their own cars: in RevLab "each car engine arrives in a car and gearbox that suit it", and Car Sounds matches each car's real-world top speed (both App Store pages, read 2026-11-12). Neither lets you type your gear ratios, axle ratio or tire size. Here the gearbox is yours: each gear's RPM comes from your numbers, every shift drops the revs by exactly new gear ÷ old gear, and all 10 engines and 3 exhausts are free with no ads and no install.

1. Your drivetrain (now)

Speed Unit Rev limiter (rpm)

Gear ratios, 1st to top (from your manual or a spec sheet)

Axle ratio (final drive) Tire size

2. The change you are thinking about

New axle ratio (regear) New tire size

Leave a box as it is now to change only one thing.

3. The engine you hear Engine

Exhaust Intake Pops on lift-off

Everything runs in this browser. Nothing is uploaded. Use headphones to hear both exhaust banks.

70 mph in 8th: 1,578 rpm now, 1,881 rpm after the change

0 rpm · neutral · off

Mode Setup

Ready to play: · · ·

Gear	Ratio	RPM now	RPM after	Speed at the limiter, now → after	Shift drop

Click a gear to hear the engine held at that RPM. Speed at the limiter is gearing only (it ignores drag and power).

The maths, written out: one mile is 63,360 inches, so the wheels turn speed × 63,360 ÷ 60 ÷ (π × tire diameter) times a minute, and the engine turns that × axle ratio × gear ratio. That gives rpm = mph × axle × gear × 336.13 ÷ tire diameter in inches. Metric tire diameter = rim + 2 × width × aspect ÷ 25.4 (245/40R18 = 18 + 2 × 245 × 0.40 ÷ 25.4 = 25.72 in). Real tires run a little smaller than the size on the sidewall when loaded. The sound is synthesized from each cylinder's firing pulses (cylinders × rpm ÷ 120 a second) through pipe and muffler models: a simulation for comparing setups, not a recording of any car and not a decibel measurement.

Pro, $2.99 a month or $19.99 a year: play now and after back to back with the same drive, save your setups in a garage, record your own run and download WAV files, back up your garage. Get Pro · $2.99 / month

Pro: now vs after A/B, garage and WAV downloads

Hear now vs after

The same drive plays on your setup now, half a second of silence, then on the setup after the change.

Drive B engine

Garage

Name this setup

Record and download

Restore backup

Your key

engine sound simulator · runs in your browser · nothing is uploaded · synthesized sound, not recorded from any car or brand

Questions and answers

What does this page do?

Engine sound simulator in the browser: enter your gear ratios, axle ratio and tire size, pick a speed, and hear your engine at the real RPM in every gear.

Is it free?

Yes. The free version on this page works without an account. The full version costs $2.99 / month.

How do I use it?

1. Enter your details in the free version below. 2. See your result right away on this page. 3. Need more? The full version adds what is listed under "What you get".