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Fuel Tracking

Jamey Starett edited this page Aug 30, 2026 · 9 revisions

Fuel Tracking

Track fuel economy, fill-ups, and fuel costs to understand your vehicle's efficiency and operating expenses.


Why Track Fuel?

  • Monitor Fuel Economy - Identify trends and detect issues early
  • Budget Fuel Costs - Track monthly/annual fuel expenses
  • Detect Problems - Sudden MPG drops indicate mechanical issues
  • Compare Vehicles - See which vehicle is most economical
  • Tax Deductions - Track business mileage and fuel costs
  • Optimize Driving - Identify behaviors that improve efficiency

Adding Fuel Entries

Quick Add

  1. From dashboard, click vehicle card → "Add Fuel"
  2. Fill in required fields:
    • Fill-Up Date - When you filled up (defaults to today)
    • Odometer Reading - Current mileage (always required)
    • Fuel Amount - Gallons or liters, matching your unit preference (required unless "Missed Fill-up" is checked)
    • Full Tank? - Check if filled to full (needed for a fuel-economy figure)
  3. Add optional details:
    • Price per Unit - Cost per gallon/liter (auto-calculates total)
    • Rebate - Points, discounts, or cash back applied to this fill-up
    • Total Cost - Amount actually paid, net of any rebate (auto-calculated, or enter manually)
    • Gas Station - Where you filled up
  4. Click "Save"

MyGarage automatically calculates:

  • Fuel economy - MPG, L/100km or km/L, whichever you have set under Units
  • Cost per distance - Fuel cost divided by distance driven
  • Cost per unit - If you enter total cost without price per unit

Detailed Fuel Entry

The full fuel form (vehicle detail page → Fuel tab → Add Fill-Up) adds optional fields beyond the quick add:

  • Fill-Up Time - Enables "Auto-fill from last drive"
  • Payment Method - Cash, Credit, Debit, Fleet Card, App, Other
  • Gas Station - Autocomplete from your address book; new stations are saved unless you check One-time visit
  • Driver - A household member or a typed name
  • Trip Type - Private, Business, Commute, Other
  • Outside Temperature
  • Trip computer (OBC) - Reported consumption, average speed, and trip duration. Auto-fill from last drive pulls these from your most recent LiveLink drive session (within 24h) when a fill-up time is set.
  • Notes - Free-form

On multi-fuel vehicles (flex / PHEV / dual-fuel), a per-fill Fuel Type dropdown records which fuel was used.

Receipt Drafting (Optional)

If you enable it under Settings → Integrations, MyGarage can read a pump receipt and pre-fill the form. Paste the text, or upload a photo or PDF.

It is off by default and needs an LLM you point it at - a local Ollama instance, or any OpenAI-compatible endpoint. Nothing is sent anywhere unless you turn this on and configure a destination.

The result is always a draft. It populates the form and waits for you to check the numbers before saving; it never writes a record on its own.


Understanding MPG Calculations

Fuel economy is shown in the unit you picked under Units: MPG, L/100km or km/L. It is stored internally as L/100km. MyGarage calculates economy using the distance-per-volume method:

How MPG is Calculated

At each full tank, MyGarage divides the distance since the previous full tank by all fuel added since then — the full fill-up plus any partial fills in between:

MPG = (Current Odometer - Previous full-tank Odometer) / (All gallons added since the previous full tank)

Example (no partials in between):

  • Previous full tank: 45,000 miles
  • Current full tank: 45,350 miles
  • Gallons added: 12.5 gallons

Calculation:

MPG = (45,350 - 45,000) / 12.5
MPG = 350 / 12.5
MPG = 28.0 MPG

Requirements for Accurate MPG

Full tank fills - MPG calculation requires filling to full each time ✅ Accurate odometer - Record mileage precisely ✅ Consistent fill method - Always fill until pump auto-stops ✅ 2+ fill-ups - First fill-up has no MPG (needs previous baseline)

ℹ️ Partial fills are handled automatically - Their fuel is folded into the next full tank's figure, so they no longer skew the numbers

First Fill-Up

The first fuel entry for a vehicle has no MPG because there's no previous fill-up to compare against. Starting with the second fill-up, MyGarage calculates MPG.

Example Timeline:

  • Fill-Up #1: 45,000 miles, 12.0 gallons → No MPG (baseline)
  • Fill-Up #2: 45,350 miles, 12.5 gallons → 28.0 MPG (first calculation)
  • Fill-Up #3: 45,700 miles, 13.0 gallons → 26.9 MPG

Partial Fill-Ups

If you can't fill to full (e.g., budget constraints, topping off), you can still track fuel costs:

  1. Add fill-up as usual
  2. Uncheck "Full Tank?"
  3. Enter gallons and cost
  4. Click "Save"

How they're handled:

  • ℹ️ A partial fill shows no economy figure of its own
  • ✅ Its fuel is counted toward the next full tank's MPG/L100km, so the figure stays accurate
  • ✅ Fuel costs still tracked

Best Practice: Just uncheck "Full Tank?" for top-offs. MyGarage rolls that fuel into the next full-tank calculation automatically — you don't need to fill to full every time for accurate trends.


Fuel Types

A vehicle's fuel type is set on the vehicle (prefilled from the VIN decode). Supported values:

  • Gasoline
  • Diesel
  • Electric
  • Hybrid
  • Plug-in Hybrid
  • E85 / Flex Fuel
  • Propane / LPG
  • CNG
  • Hydrogen
  • Other

Octane grades and diesel sub-grades (87/89/91, B20, etc.) are not tracked separately.

Propane (Fifth Wheels & RVs)

  • Propane - For RVs, fifth wheels, and travel trailers
    • Tracked separately from motor fuel
    • Dedicated propane tab (visible for RVs, fifth wheels, and travel trailers)
    • Track volume, cost, price per unit, vendor
    • Analytics show propane spending trends and cost per unit

How to Track Propane:

  1. Add vehicle as type "RV", "FifthWheel", or "TravelTrailer"
  2. Navigate to vehicle detail page
  3. Click "Propane" tab
  4. Click "Add Propane Fill"
  5. Fill in:
    • Date - When filled
    • Propane Volume - Gallons or liters, matching your unit preference (required)
    • Cost - Total cost (required)
    • Price per Unit - Auto-calculated or manual entry
    • Vendor - Where you filled (optional)
    • Notes - Any additional details
  6. Click "Save"

Note: RVs can track both motor fuel (diesel/gasoline) AND propane separately. Fifth wheels and travel trailers track propane only (no motor fuel or odometer). See Fifth Wheels & RVs.

Electric Vehicles (EVs)

MyGarage now supports Electric and Hybrid vehicles with smart charging tracking:

Supported Vehicle Types:

  • Electric - Pure electric vehicles (track kWh only)
  • Hybrid - Plug-in hybrids (track both gallons AND kWh)

How to Track EV Charging:

  1. Add vehicle as type "Electric" or "Hybrid"
  2. Navigate to vehicle detail page
  3. Click "Fuel" tab (shows smart form based on vehicle type)
  4. Click "Add Fuel/Charging Record"
  5. Fill in required fields:
    • Date - When you charged
    • Odometer Reading - Current mileage (required for efficiency calculations)
    • kWh Added - Energy charged (required for electric vehicles)
    • Gallons - For hybrid vehicles only (optional for pure electric)
  6. Add optional pricing:
    • Price per kWh - Cost per kilowatt-hour (e.g., $0.12)
    • Total Cost - Total amount paid (auto-calculated from kWh × price)
  7. Click "Save"

Smart Form Behavior:

  • Electric vehicles: Form shows kWh field only (hides gallons, full tank checkbox, hauling checkbox)
  • Hybrid vehicles: Form shows BOTH gallons and kWh fields (track gas and electric usage)
  • Form auto-calculates: Total cost from kWh × price per kWh

Charge Session Details (optional, on any record with kWh):

  • State of charge - the battery percentage at the start and end of the session
  • Charge level - Level 1, Level 2, or DC fast charging
  • Location - home or public
  • Battery health - state of health as a percentage, to watch degradation over time

All five are optional. Fill in what you have; a session with only kWh still counts toward efficiency.

EV Analytics:

  • kWh/100mi - Energy efficiency (replaces MPG for electric vehicles)
  • Charging costs - Total spent on electricity vs gasoline (for hybrids)
  • Cost per mile - Operating cost for electric driving
  • Monthly trends - Visualize charging patterns and costs

Fuel Analytics

MyGarage provides rich analytics for fuel tracking:

Fuel Economy Trends

MPG Over Time (line chart):

  • Visualize MPG trends month-by-month
  • Identify seasonal variations (winter MPG drops)
  • Detect sudden changes (may indicate issues)

Average MPG:

  • Last 3 fill-ups - Recent short-term average
  • Last 10 fill-ups - Medium-term average
  • Last 12 months - Long-term average
  • Lifetime - All-time vehicle average

Cost Analysis

Fuel Cost Over Time (bar chart):

  • Monthly fuel spending
  • Compare year-over-year costs
  • Budget planning

Cost per Mile:

  • Total fuel cost ÷ total miles driven
  • True cost of driving
  • Compare against service costs for total operating expense

Price per Gallon Trends:

  • Track fuel price changes over time
  • Find cheapest gas stations
  • Identify price seasonality

Missed Fill-Ups

If you forgot to log a previous fill-up, check "Missed Fill-up" on your next entry. This lets you save with just the odometer reading when you don't have the fuel amount.

A missed fill-up produces no economy figure of its own and is excluded from the vehicle's average — MyGarage no longer stretches one tank's fuel across the gap (which understated consumption). The sequence re-anchors, so economy resumes on the next full fill-up.


Exporting Fuel Data

Open the vehicle's Fuel tab and click Export to download every fill-up as a CSV.

For a formatted PDF report with charts, use the vehicle's Analytics page instead — see Analytics.

Exports Use Your Units

The file is written in the units you read the app in. If you read miles, gallons and price per gallon, that is what you get; a metric reader gets kilometres, litres and price per litre. You don't have to choose, MyGarage uses the units you already have set.

Each column names its own unit, in the header: Odometer (mi), Volume (gal_uk), Price Per Unit (gal_us). Import takes each column's unit from the file rather than from your account, so a file exported by someone using different units still imports correctly. Older files that carried the unit system in two leading columns (units_version and unit_system) still import unchanged. Those exist so that re-importing your own export converts the values back correctly instead of guessing. Leave them in place if you edit the file in a spreadsheet.

Values are stored internally in metric no matter what you export, so switching your display units never alters the underlying data.

US or UK Gallons

Pick the gallon you mean under Settings → System → Units: the US gallon (3.785 L) or the UK / imperial gallon (4.546 L). Volume and MPG have separate controls, because MPG names a gallon even if you fill up in litres.

The standalone US/UK gallon switch that used to live in Settings → System is gone; these controls replace it. If your instance was set to UK gallons before upgrading, nothing you read changes, but some older prices may read about 20% high: a price entered while the instance was already on UK gallons was stored too high by that factor. Re-entering the price you actually paid corrects it. See Units for the details.

The two differ by about 20%, so this is worth setting before you log much. UK drivers who leave it on the US default will see MPG figures noticeably lower than the ones on their dashboard.

Round-Tripping

Exporting a CSV, editing it, and importing it again is a supported workflow — bulk-correcting old records in a spreadsheet is much faster than clicking through them one at a time.

Fixed in v3.0.0: earlier versions mis-read their own exports on re-import, multiplying distances by 1.609 and volumes by 3.785 on every round trip, and imperial imports recorded price per gallon as though it were per litre. If you imported fuel data on an older version, upgrading repairs the affected price records automatically. Distances and volumes inflated by repeated round trips cannot be recovered automatically — check a few older records against your receipts.

Other Exports

CSV export is also available for service visits, DEF and odometer records, and they follow your units the same way. Engine-hours, warranty, insurance, tax and note exports are unaffected by units, since hours and currency aren't converted. The LiveLink session export is the one exception that stays metric for everyone, writing distance_km and raw km/h speeds.

Report CSVs cannot be imported. A report is a printable summary rather than a backup, and importing an all-records report used to create a service visit out of every fuel fill-up. MyGarage now refuses one with a clear error. Backups from Export still import, older files included.

A whole-vehicle JSON export is available too. It always stores metric with explicitly named fields (odometer_km, liters), so it is unambiguous and round-trips safely regardless of your display preference.

Use Cases:

  • Tax deductions (business mileage)
  • Expense reports (company vehicle reimbursement)
  • Personal budgeting
  • Bulk-editing records in a spreadsheet

Importing From Another App

The Fuel tab's Import action reads MyGarage's own CSV plus exports from other trackers:

  • Fuelio
  • Drivvo
  • Tesla / ABRP charge exports
  • Auto-detect, if you are not sure which you have

Pick the odometer unit and the decimal separator on the import form. MyGarage asks rather than guessing, because a file using 528,25 for a decimal comma is indistinguishable from one using a thousands comma, and guessing wrong silently corrupts every row.

Re-importing a file you corrected in the source app is safe. Records are matched on the fill's own timestamp, so two charge sessions on the same day stay separate and a re-import updates rather than duplicates.


Fuel Tracking Best Practices

Log Every Fill-Up

  • Always log - Even on road trips, gas station apps, etc.
  • Record immediately - Don't wait, you'll forget details
  • Use mobile app (if available) - Log at the pump

Fill to Full Every Time

  • Full tank - Let pump auto-stop, don't round up
  • Consistent method - Same pump nozzle depth, same station type
  • Don't top off - Adds inconsistent amounts, skews MPG

Record Accurate Odometer

  • Check before filling - Record mileage before pumping
  • Use vehicle odometer - Don't estimate from trip meter
  • Don't round - 45,342 miles, not "about 45,000"

Troubleshooting MPG Issues

MPG Suddenly Dropped

Possible Causes:

  • Clogged air filter → Replace filter
  • Bad spark plugs → Replace plugs
  • Low tire pressure → Check/inflate tires
  • Dirty fuel injectors → Use fuel system cleaner
  • Oxygen sensor failure → Check engine light, scan codes
  • Driving habits changed → More city driving, aggressive acceleration

Action:

  1. Check service records - When was last tune-up?
  2. Compare recent fill-ups - Sudden drop or gradual?
  3. Inspect vehicle - Tire pressure, air filter, check engine light
  4. Add service record if repair performed

Inaccurate MPG Calculation

Possible Causes:

  • Missed fill-up → Check "Missed Fill-up" so the gap is excluded, not bridged
  • Partial fill → Uncheck "Full Tank?" to exclude from economy
  • Odometer error → Verify odometer reading accuracy
  • Different pump shutoff → Some pumps shut off early/late

Action:

  1. Review recent fill-ups for errors
  2. Edit fill-up to correct odometer or gallons
  3. Mark partial fills appropriately

Wildly High MPG (e.g., 60 MPG on a truck)

Possible Causes:

  • Missed fill-up (shows 2x distance on 1 tank)
  • Odometer entry error (extra digit)
  • Gallons entry error (half the actual amount)

Action:

  1. Review last 2 fill-ups
  2. Check for missed fill-up between them
  3. Verify odometer readings
  4. Correct errors

Fuel Economy Tips

Improve MPG with these tips:

Driving Habits

  • Accelerate gently - Avoid jackrabbit starts
  • Maintain steady speed - Use cruise control on highway
  • Coast to stops - Don't brake aggressively
  • Avoid idling - Turn off engine if stopped > 1 minute

Vehicle Maintenance

  • Proper tire pressure - Check monthly, inflate to spec
  • Clean air filter - Replace every 12,000-15,000 miles
  • Synthetic oil - Reduces friction, improves efficiency
  • Tune-ups - Replace spark plugs on schedule

Reduce Weight & Drag

  • Remove roof racks - When not in use
  • Clear trunk - Remove unnecessary cargo
  • Windows up at highway speeds - Reduces drag

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