TL;DR - I continue to get better gas mileage with the new 5th gear. Still collecting data.
Every tank lasts longer than it used to. Barely.
This is a very short update, mostly because I assume that folks will be curious to know how the fuel economy is working out with the new 5th gear from an R452 transmission.
Everything I wrote in my First Impressions (see "In This Series" below) continues to be true. There, I also posted my initial MPG numbers for the first 1,500 miles of highway travel. I've completed another 3,600 miles, and wanted to provide another update.
| 5th Gear | Year | Miles | MPG | Average MPG |
|---|---|---|---|---|
| R150F | 2018 | 10,787 | 17.34 | 17.48 |
| 2019 | 20,383 | 16.96 | ||
| 2020 | 17,695 | 17.50 | ||
| 2021 | 29,529 | 17.80 | ||
| 2022 | 24,403 | 17.61 | ||
| 2023 | 10,662 | 17.35 | ||
| 2024 | 8,061 | 17.64 | ||
| R452 | 2024 (first update) |
1,466 | 18.24 | 17.86 |
| R452 | 2024 (remainder) |
374 | 16.54 | |
| R452 | 2025 (through May 3) |
3,285 | 18.15 | 18.15 |
That puts the R452 5th gear at a total of 5,092 miles with an average 18.05 MPG. Still better than pre-R452 - especially taking into account the heavier and wider wheel-tire combo - but less of a gain than the first few spectacular tanks immediately after the swap in 2024.
I will say - I was thrilled to see a 357-mile tank on the drive home from Utah that averaged 21.164 MPG! Had a nice tailwind there, between Salina, UT and Twin Falls, ID.
Look for another update one year from now.
In this Series
