UltraLog provides comprehensive unit conversion for 8 measurement categories. This page details all available options and conversion formulas.
Overview
- Access unit settings via the Units menu
- Changes apply immediately to all displayed values
- Original data is never modified - conversions are display-only
- Preferences are maintained for the session
Temperature
Available Units
| Unit |
Symbol |
Description |
| Kelvin |
K |
SI base unit |
| Celsius |
°C |
Metric standard |
| Fahrenheit |
°F |
Imperial standard |
Celsius = Kelvin - 273.15
Fahrenheit = (Kelvin - 273.15) × 9/5 + 32
ECU Data Notes
- Haltech: Stores temperature in Kelvin
- ECUMaster: Typically in Celsius
- Speeduino: Varies by configuration
Common Temperature Channels
- Coolant Temperature
- Intake Air Temperature (IAT)
- Oil Temperature
- Exhaust Gas Temperature (EGT)
- Fuel Temperature
Pressure
Available Units
| Unit |
Symbol |
Description |
| Kilopascals |
kPa |
SI standard |
| PSI |
psi |
Pounds per square inch |
| Bar |
bar |
Metric bar |
PSI = kPa × 0.145038
Bar = kPa × 0.01
Common Pressure Channels
- Manifold Absolute Pressure (MAP)
- Boost Pressure
- Oil Pressure
- Fuel Pressure
- Barometric Pressure
Understanding MAP Values
| kPa |
psi |
bar |
Condition |
| 101.3 |
14.7 |
1.01 |
Atmospheric (sea level) |
| 50 |
7.25 |
0.5 |
Vacuum (naturally aspirated) |
| 150 |
21.8 |
1.5 |
~7 psi boost |
| 200 |
29.0 |
2.0 |
~14 psi boost |
| 250 |
36.3 |
2.5 |
~21 psi boost |
Speed
Available Units
| Unit |
Symbol |
Description |
| Kilometers per hour |
km/h |
Metric standard |
| Miles per hour |
mph |
Imperial standard |
mph = km/h × 0.621371
Common Speed Channels
- Vehicle Speed
- Wheel Speed (individual wheels)
Distance
Available Units
| Unit |
Symbol |
Description |
| Kilometers |
km |
Metric standard |
| Miles |
mi |
Imperial standard |
miles = km × 0.621371
Common Distance Channels
- Trip Distance
- Odometer
- GPS Distance
Fuel Economy
Available Units
| Unit |
Symbol |
Description |
| Liters per 100km |
L/100km |
Metric (lower is better) |
| Miles per gallon |
MPG |
Imperial (higher is better) |
MPG = 235.215 / L/100km
Note: These units are inversely related - L/100km measures fuel consumption while MPG measures fuel efficiency.
Interpretation Guide
| L/100km |
MPG |
Efficiency |
| 5 |
47 |
Excellent |
| 8 |
29 |
Good |
| 12 |
20 |
Average |
| 15 |
16 |
Poor |
| 20 |
12 |
Very Poor |
Volume
Available Units
| Unit |
Symbol |
Description |
| Liters |
L |
Metric standard |
| Gallons |
gal |
US gallon |
gallons = liters × 0.264172
Common Volume Channels
- Fuel Level
- Fuel Used
- Tank Capacity
Flow Rate
Available Units
| Unit |
Symbol |
Description |
| Liters per minute |
L/min |
Metric standard |
| Gallons per minute |
GPM |
Imperial standard |
GPM = L/min × 0.264172
Common Flow Rate Channels
- Fuel Flow
- Air Flow
- Water/Coolant Flow
Fuel Flow Reference
| L/min |
GPM |
Approximate Power (gasoline) |
| 0.5 |
0.13 |
~100 HP |
| 1.0 |
0.26 |
~200 HP |
| 1.5 |
0.40 |
~300 HP |
| 2.0 |
0.53 |
~400 HP |
Note: Actual power depends on BSFC and other factors
Acceleration
Available Units
| Unit |
Symbol |
Description |
| Meters per second squared |
m/s² |
SI standard |
| Gravitational force |
g |
Earth gravity reference |
g = m/s² / 9.80665
Reference Values
| m/s² |
g |
Context |
| 9.81 |
1.0 |
Earth gravity |
| 4.9 |
0.5 |
Moderate acceleration |
| 9.8 |
1.0 |
Hard braking/acceleration |
| 14.7 |
1.5 |
Very hard maneuver |
| 19.6 |
2.0 |
Extreme (racing) |
Common Acceleration Channels
- Longitudinal G (acceleration/braking)
- Lateral G (cornering)
- Vertical G (suspension movement)
Default Units
UltraLog uses these defaults:
| Category |
Default |
| Temperature |
Celsius |
| Pressure |
kPa |
| Speed |
km/h |
| Distance |
km |
| Fuel Economy |
L/100km |
| Volume |
Liters |
| Flow Rate |
L/min |
| Acceleration |
m/s² |
How Unit Conversion Works
Data Flow
- Raw Data - ECU logs data in native format
- Parser - Converts to base units (Kelvin, kPa, etc.)
- Storage - Data stored in base units
- Display - User preference conversion applied
- Legend - Shows converted value with unit symbol
Example
Haltech logs coolant temp as 363.15 (Kelvin)
→ Parser reads raw value: 363.15 K
→ Stored in memory: 363.15 K
→ User preference: Celsius
→ Displayed: 90.0 °C
→ If changed to Fahrenheit: 194.0 °F
Why Base Units?
Using base units internally:
- Ensures consistency across ECU formats
- Simplifies conversion logic
- Prevents cumulative rounding errors
- Allows instant unit switching
Tips
Choosing Units
- Use units familiar to your region/industry
- Match units to your reference documentation
- Consider your audience if sharing exports
Comparing Data
- Use the same units when comparing logs
- Note that some ECUs log in different units
- Field Normalization helps standardize naming
Troubleshooting
If values seem wrong:
- Check your Unit Preferences
- Verify the ECU's native units
- Some channels may not support unit conversion
Next Steps
From the GitHub wiki. Edit this page