Detroit DT12 vs Allison 4000 Series
Specs, oil interval and warranty compared
Transmission comparison
The Detroit DT12 is an automated manual transmission with 12 forward gears, listed for on-highway Freightliner trucks. The Allison 4000 Series is a fully automatic transmission with six or seven forward gears, listed for construction, refuse, mining, fire and other vocational uses. The DT12 lists up to 2,250 lb-ft. The Allison lists up to 2,360 lb-ft of input torque and 380 to 800 hp. Detroit prints oil intervals. Allison's pages we read do not. They are built for different jobs, so there is no spec-sheet winner.
Figures for DT12 vs Allison 4000 are taken from the makers' own published documents. Last reviewed November 3, 2026.
DT12 vs Allison 4000: side-by-side specs
| Spec | Detroit DT12 | Allison 4000 Series |
|---|---|---|
| Type | Automated manual (AMT) | Fully automatic (not an automated manual) |
| Speeds | 12 forward, 4 reverse | 6 or 7 forward, depending on the model |
| Torque | 2,250 lb-ft (HE), 2,050 lb-ft (middle), 1,650 lb-ft (HL) | Maximum input torque 2,360 lb-ft (3,200 N·m) |
| Engine power | Not stated as a horsepower range | 380–800 hp (283–597 kW) |
| Weight | Not stated in pounds | Not stated on the 4000 Series pages |
| Fluid | MB 235.16 (75W-85) on 2017 and newer; MB 235.11 (75W-90) on 2016 and older | Allison TES 668 recommended; TES 295 and TES 468 also approved |
| Oil interval | From 180,000 miles or 3 years (severe) to 400,000 miles or 5 years (line haul up to 80,000 lb); up to 600,000 miles with the Maintenance System | Not listed on the pages we read. Allison points to its change recommendations document and its Fluid + Filter Calculator |
| Warranty as printed by the maker | Not stated on the pages we read | Not stated on the pages we read |
| Jobs the maker lists | On-highway trucks (the page we read is Detroit's on-highway series) | Construction, defense, fire and emergency, mining and specialty, oil and gas, pickup and delivery, refuse and utilities, RV, transit and coach bus |
| Trucks | Freightliner Cascadia, M2 112 Plus, 114SD Plus | Kenworth T880 and Peterbilt 567 with the PACCAR MX-13 (July 2025 Allison release) |
Full detail for each transmission: Detroit DT12 guide and Allison 4000 Series guide.
What actually decides DT12 vs Allison 4000?
We do not name a winner in DT12 vs Allison 4000. There is no independent, like-for-like study of fuel economy or reliability for these transmissions. These are the facts that decide it for a given truck and duty cycle.
- Start with the job
- Allison lists construction, refuse, mining, fire and emergency, and similar work. Detroit's DT12 on-highway page covers highway trucks. If your truck spends its day on the highway, you are looking at the DT12 class. If it works stop-and-go with a PTO, you are looking at the Allison class.
- A clutch or no clutch
- The DT12 is a manual gearbox with a computer that runs the clutch and shifter. The Allison is a full automatic. They are different designs, so the intervals, the repairs and the wear points are different too.
- Compare intervals only after you have the Allison table
- Detroit prints DT12 oil intervals by duty. Allison's 4000 Series pages do not. Allison points to a change recommendations document and a Fluid + Filter Calculator on the Allison HUB. Use those before you compare the two.
- Look at the engine and truck
- Detroit pairs the DT12 with its DD engines in Freightliner trucks. Allison's July 2025 release lists the 4000 Series with the CARB low-NOx PACCAR MX-13 in the Kenworth T880 and Peterbilt 567. The engine and truck you want will often settle the choice before the spec sheet does.
Put your DT12 vs Allison 4000 oil changes on a schedule with the maintenance scheduler. Decode warning lights with the fault code lookup. Before you buy a used truck, run the VIN decoder and the used truck inspection checklist.
More transmission comparisons and guides
DT12 vs Allison 4000 frequently asked questions
Is the Detroit DT12 better than the Allison 4000 Series?+
They are built for different work, and no independent study compares them. The DT12 is an automated manual listed for on-highway Freightliner trucks. The Allison 4000 Series is a full automatic listed for vocational jobs such as construction, refuse and mining. Pick by job, not by spec sheet.
What is the difference between a DT12 and an Allison automatic?+
The DT12 is an automated manual: a manual gearbox with a computer-run clutch. The Allison 4000 Series is a fully automatic transmission. The DT12 has 12 forward gears. The Allison has six or seven.
Do the DT12 and the Allison 4000 use the same fluid?+
No. The DT12 uses Mercedes-Benz specs, MB 235.16 (75W-85) or MB 235.11 (75W-90), depending on the model year. Allison recommends its TES 668 for 4000 Series on-highway units, and approves TES 295 and TES 468. Volvo says its I-Shift oil is not for Allison transmissions.
Which handles more torque, the DT12 or the Allison 4000?+
Detroit lists up to 2,250 lb-ft for the DT12-HE. Allison lists a maximum input torque of 2,360 lb-ft for the 4000 Series. Both are listed as maximum input torque, so Allison's figure is 110 lb-ft higher on paper. What matters is the rating for your own engine, so check that before you compare.
Which has the longer oil change interval, the DT12 or the Allison 4000?+
Detroit lists 180,000 miles for severe duty up to 400,000 miles for line haul, and up to 600,000 with the Maintenance System. Allison does not list an interval on its 4000 Series pages. It points to a change recommendations document and a Fluid + Filter Calculator. There is no fair interval comparison without that table.
Sources for DT12 vs Allison 4000
Choosing between DT12 vs Allison 4000? Let a dispatcher help.
Grow Trucking finds loads, negotiates rates and does the paperwork for owner-operators and small fleets. Tell us what you haul and we will show you how a DT12 vs Allison 4000 truck fits the lanes we book.
Also: About Grow Trucking · Refer a carrier · Trucking blog
Ratings, intervals and warranty terms for DT12 vs Allison 4000 change by model year and configuration. Confirm exact figures for a specific truck against the makers' current documents and your written warranty before you buy or set a service schedule.
Free tools for a DT12 vs Allison 4000 decision
Keep a DT12 vs Allison 4000 truck serviced on time, decode its fault codes and check a truck before you buy.
- Preventive Maintenance SchedulerTrack oil changes for a DT12 vs Allison 4000 truck by odometer and duty cycle.
- Diesel Fault Code Lookup (SPN/FMI)Decode the SPN/FMI fault codes either DT12 vs Allison 4000 transmission reports.
- Breakdown Cost EstimatorEstimate what a breakdown costs in repairs and lost revenue on a DT12 vs Allison 4000 truck.
- Used Truck Inspection ChecklistCheck the transmission and clutch on a DT12 vs Allison 4000 truck before you buy it used.