Skip to content

EFI Analytics

TunerStudio MSL logs

Legacy ASCII datalogs from TunerStudio and RealDash.

.mslSample logDownload UltraLog
  • File type: Tab-delimited legacy ASCII datalogs (.msl)
  • Where they come from: TunerStudio's Data Logging menu, and third-party dashes that write the same dialect — notably RealDash, which logs a Speeduino over Bluetooth straight to .msl with no cable and no conversion step
  • Supported devices: Speeduino, MegaSquirt, and any ECU logged through TunerStudio or RealDash
  • Features: Units read from the row beneath the header, optional firmware/capture-date preamble, MARK lines skipped, blank and non-numeric fields carried forward from the last known value, clock columns converted to seconds since midnight, monotonic time enforced across concatenated sessions

Format Layout

Time    SecL    RPM     MAP     ...     GPS Latitude    GPS Longitude   GPS Time
sec     s       RPM     kPa     ...     lat             lon             time
0.0     202.0   965.0   33.0    ...     -26.253315      -51.06884       21:51

Row 1 is the channel names, row 2 is the unit for each column, and everything after is data. UltraLog reads the time unit from that second row, so a log in milliseconds scales correctly instead of being read as seconds.

Supported Data

  • RPM, MAP, TPS, MAT, CLT, Battery Voltage
  • AFR and AFR2, EGO corrections
  • Pulse Width, VE, Duty Cycle (per bank)
  • Spark Advance, MAF, Boost (bar and psi), Acceleration
  • Speed, and GPS Latitude / Longitude / Altitude / Speed / Date / Time

Important Notes

  • Track Map works out of the box: GPS columns keep their exported names, so a logged session draws the track with lap detection and channel coloring
  • Non-numeric columns: GPS Date is text (18.8.2026) and has no numeric meaning, so it reads as the last known value. GPS Time is converted to seconds since midnight and does plot
  • Blank fields: RealDash leaves GPS fields blank until it gets a fix. Those rows carry the previous value forward rather than dropping to zero mid-log
  • Not the same as the MegaSquirt CSV: TunerStudio's comma-delimited CSV export is handled by the MegaSquirt parser above. Both are supported; UltraLog picks the right one automatically