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
Breaking the 20 mpg barrier takes a feather-like foot. I've done it just a handful of times in my '98 4Runner. Personal best for a tank is 28 mpg heading south (downhill) out of the Owens Valley. City tires and a 50 mph tailwind certainly helped, lol.
Yeah, I've had only a handful of tanks over 20 MPG; understandable given that such amazingly high numbers were never part of the Tacoma promise, even when brand new and all stock, lol.
Fully loaded for a trip and built out as it is, I'm continuing to see numbers in the 18s and 19s, which is amazing. Still not "worth it" monetarily given what the new gears cost, but fun from an "I'm competitive with myself and always trying to get see if I can beat my average" perspective.