Context
Why the numbers matter.
Every dollar has to justify itself, so the car has to prove it belongs.
Work van
28.0¢ /mi
2015 Express 2500, 13 mpg
This car, measured
12.9¢ /mi
energy, across 3,426.7 mi
A year, van vs. this car
$3,551
at this car’s 1,962 mi a month
The fleet, in order
| Period | Vehicle | Role | EPA combined |
|---|---|---|---|
| Sep 2025 to Jul 2026 | 2015 Chevrolet Express 2500 Cargo | Detail van, dealership runs plus detail jobs 1 to 2 weekends a month | 13 mpg |
| Jul 2026 | 2011 Toyota Sienna Limited | Interim daily driver | 20 mpg |
| Jul to Aug 2026 (15 days) | 2016 Toyota Sequoia Platinum 2WD | Interim daily driver | 15 mpg |
| Aug 2026 | 2011 Toyota Sienna Limited | Interim daily driver, second stint | 20 mpg |
| Aug 2026 (5 days) | Lexus ES300h | Stopgap, immediately before this car | 44 mpg |
| Aug 22, 2026 → | 2024 Model Y Long Range AWD | Current |
Every row below is priced at this car’s own pace, so each one covers the same driving. The gas rows are modeled; this car’s is measured.
Cost per mile, at Tennessee’s pump price
| Vehicle | Efficiency | Per mile | A month | A year |
|---|---|---|---|---|
| 2024 Model Y (this car) | 309.5 Wh/mi | 12.9¢ measured | $253 | $3,042 |
| 2015 Chevrolet Express 2500 | 13 mpg | 28.0¢ | $549 | $6,592 |
| 2016 Toyota Sequoia Platinum 2WD | 15 mpg | 24.3¢ | $477 | $5,721 |
| 2011 Toyota Sienna Limited | 20 mpg | 18.2¢ | $357 | $4,285 |
| Lexus ES300h | 44 mpg | 8.3¢ | $163 | $1,954 |
Gas figures use each vehicle’s EPA combined rating at Tennessee’s statewide average of $3.64/gal (AAA, August 24, 2026). This car’s figure is not an estimate: it is $442.62 of charging across 3,426.7 miles, priced from the carmaker’s invoices, so the energy lost on its way into the battery is already inside it. To price home charging at your own rate, use Your Numbers; the Ledger shows the same energy at other prices.
Two things only direct API access could show (Aug 27, 2026).
First, charging loss is real and measurable: the carmaker billed 43.484 kWh at Percy Priest Drive while the battery
recorded 39.4 kWh arriving, a 9.4% loss between the plug and the pack in that one session; across
28 sessions reconciled since, the loss averages 7.44%. Every per-mile figure
that ignores it understates cost. Second, the FSD (Supervised) share is higher than previously published:
259.4 of 264.7 miles, or 98%, across three consecutive days, including one day at
100%. Across every logged mile, the share is 94.5%. Charging history came from the carmaker’s own charging invoices, which hold sessions no third-party tracker
had, and the battery-side figure came from telemetry. Neither number exists without both sources.
Why this section exists. Every other comparison in this document, and the one the car's app shows, measures this car against something in the high-20s or low-30s mpg. Nothing in that range was ever actually owned. The real bar was 13 to 20 mpg, and against that bar the Model Y wins on Supercharging alone, before a home charger is ever installed.
Where these numbers are soft. The three mpg figures are EPA combined ratings, not measured tank averages for these specific vehicles, so they carry the usual EPA optimism. A loaded detail van doing short local stops realistically ran nearer 11 to 12 mpg than 13, and the Sienna Limited is rated 18 mpg rather than 20 if it was the all-wheel-drive version. Both corrections widen the gap in this car’s favor, so the table above is the conservative reading. The 309.5 Wh/mi figure is measured driving consumption. The 12.9¢ a mile is higher because it also carries idle drain and the measured 7.44% charging loss, and it will rise in winter and in traffic.
Follow the miles
Every week’s miles, charging and cost per mile, straight from the car, in the feed.