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US diesel $4.049 per gallonWeek ending Aug 17, 2026 · EIA
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PACCAR TX-12

12 speedAutomated manual2017 to present

PACCAR's own automated 12-speed, built on ZF architecture and calibrated with the MX engines. Completes the in-house Kenworth and Peterbilt drivetrain.

Torque rating

1650-1850

pound-feet at the input

Weight

680 lb

40 lb over the lightest, which is payload

Shifting

Actuated

software decides the gear

Maker

PACCAR

What it does to fuel

Competitive with the DT12 and I-Shift when paired with an MX-13 and a tall axle. The gains come from the same downspeeding logic.

What this type is

The same gearbox with the clutch and the shifting actuated. It is NOT an automatic, it has no torque converter, and it fails and gets repaired like a manual. This is now the default in new linehaul, because software shifts more consistently than a person and consistency is fuel.

Known issues

Recent enough that the long-term record is thin, and parts route through PACCAR dealers rather than the independent network.

Verdict

Good, and it ties you further into the PACCAR dealer channel. Check coverage on the lanes you run before choosing it over an Endurant.