Speed Dash

Speed Dash - Accurate GPS Speedometer Purpose Speed Dash is designed to help users verify the accuracy of their vehicle's speedometer by comparing it with GPS-based speed measurements. Most vehicle speedometers have a built-in margin of error (typically showing 5-10% higher than actual speed), and this app allows you to see the difference in real-time. Key Features Real-Time GPS Speed: Displays your current speed based on GPS data Multiple Units: Switch between km/h, mph, m/s, and knots Speed History Graph: Visualizes speed changes over time Altitude Tracking: Shows your current altitude and changes over time Signal Quality Indicator: Displays GPS accuracy and signal strength Location Coordinates: Shows your current latitude and longitude Dark Mode Optimized: Clean interface that works well in all lighting conditions How to Use Open the app and grant location permissions when prompted Mount your device securely in your vehicle Start driving and observe both your vehicle's speedometer and the GPS speed Toggle between different speed units using the unit indicator View your speed history in the graph at the bottom of the screen Compare altitude changes as you drive through varying elevations Technical Details: GPS Speed vs. Vehicle Speedometer Vehicle Speedometer Accuracy Most vehicle speedometers are designed to display a speed that is slightly higher (typically 5-10%) than your actual speed. This is intentional and serves several purposes: Legal protection: Manufacturers avoid liability from drivers inadvertently speeding Tire wear: As tires wear down, speedometer readings can change Safety margin: Encourages drivers to drive slightly under the speed limit GPS Speed Measurement GPS speed is calculated by measuring the distance traveled between satellite pings and is generally more accurate than mechanical speedometers: Accuracy: Typically within 0.1-0.2 km/h (0.06-0.12 mph) when good signal is available No mechanical variables: Not affected by tire size, wear, or pressure Signal-dependent: Requires good satellite visibility for optimal accuracy Factors Affecting Accuracy GPS signal quality: Accuracy decreases in tunnels, dense urban areas, or heavy tree cover Device position: Best results when device has clear view of the sky Update frequency: The app updates speed multiple times per second for smooth readings Requirements iOS 18.3 or later iPhone or iPad with GPS capability Location Services enabled Privacy This app uses location services only when the app is active. No location data is collected or transmitted to external servers. Location data is only used locally to calculate and display your speed and altitude.