2025 Ram Heavy Duty Maintenance Schedule
Ram 2500 & 3500 Service Intervals for the 6.4L HEMI V8 and 6.7L Cummins High Output Turbo Diesel
Proudly serving Brevard, Asheville, Hendersonville, Fletcher & Cherokee NC
2025 Ram Heavy Duty Scheduled Maintenance Overview
The 2025 Ram 2500 and 3500 are the first year of the refreshed Ram Heavy Duty, and they share two engines: the 6.4L HEMI V8 (405 hp / 429 lb-ft), standard on every trim, and the all-new 6.7L Cummins High Output Turbo Diesel I-6 (430 hp / 1,075 lb-ft), available on every trim except the Ram 2500 Power Wagon. The standard-output Cummins is gone, and both engines use the TorqueFlite HD 8-speed automatic. Gas and diesel follow different service plans with very different oil specs, capacities, filters and intervals, so know which engine is under your hood. Our Mopar-certified team handles both with OEM-spec parts.
The 2025 Ram 2500 and 3500 use the Stellantis Oil Change Indicator System. On the HEMI, the owner's manual says to never exceed 8,000 miles, 12 months or 350 engine hours between oil changes and to check the oil level every 3,000 miles. The Cummins High Output plan allows up to 15,000 miles or 12 months between oil changes, while its 7,500-mile / 6-month columns cover tire rotation, DEF refills and front-end lubrication. Heavy towing, dusty roads and mountain grades all bring the indicator on sooner.
Oil & Filter
HEMI: Oil Change Indicator; max 8,000 mi / 12 months / 350 hours
Cummins HO: max 15,000 mi / 12 months
Tire Rotation
HEMI: every 10,000 mi / 1 year (sooner at irregular wear)
Cummins: every 7,500 mi / 6 months
Cabin Air Filter
Every 12,000 mi (both engines)
Mopar 68548579AA
Spark Plugs
HEMI: 100,000 mi (16 plugs, mileage based)
Cummins: none; two fuel filters every 15,000 mi
Complete Maintenance Schedule by Mileage
| Mileage Interval | Services Performed |
|---|---|
| Every 7,500 miles / 6 months | Check DEF tank and refill; rotate tires; inspect and lubricate front end (serviceable fittings); inspect CV/universal joints |
| Every 8,000 miles (Oil Change Indicator; max 8,000 mi / 12 months / 350 engine hours) | Change engine oil and filter; inspect exhaust; check tire pressure and rotate at first sign of irregular wear; inspect batteries/terminals; inspect CV/universal joints; inspect brake pads, shoes, rotors, drums, hoses and parking brake; inspect cooling system and hoses; inspect and lubricate front end (serviceable fittings); clean/grease power side steps; inspect engine air cleaner (dusty/off-road); inspect/replace evaporative fresh-air filter as necessary |
| Every 10,000 miles / 1 year (table columns) | Rotate tires; inspect CV/universal joints |
| Every 12,000 miles | Replace cabin air filter |
| Every 12,000 miles | Replace cabin air filter |
| Every 15,000 miles / 12 months | Replace front (chassis/engine-mounted) fuel filter and rear engine-mounted fuel filter (Mopar 68677800AA set); inspect engine air cleaner filter (replace if necessary; never exceed 30,000 mi / 24 months); inspect front suspension, tie rod ends and boot seals |
| Every 15,000 miles (Oil Change Indicator; max 15,000 mi / 12 months) | Change engine oil and filter; inspect exhaust; rotate tires at first sign of irregular wear; inspect batteries; inspect CV/universal joints; inspect brakes; inspect cooling system; lubricate front end; inspect engine air cleaner |
| Every 20,000 miles / 2 years | Inspect front suspension and tie rod ends; inspect front/rear axle surfaces (change axle fluid for police, taxi, fleet, off-road, frequent trailer towing); inspect brake linings; adjust parking brake |
| Every 22,500 miles / 18 months | Inspect brake linings; inspect and adjust parking brake; inspect drive belt (replace as necessary); inspect front/rear axle surfaces (change axle fluid for police, taxi, fleet, off-road, frequent trailer towing) |
| 30,000 / 90,000 / 150,000 miles | Inspect transfer case fluid |
| Every 30,000 miles / 24 months | Inspect wheel bearings; inspect transfer case fluid (4x4) and change for police, taxi, fleet or frequent trailer towing; engine air cleaner filter must be replaced by 30,000 mi / 24 months at the latest |
| Every 30,000 miles / 3 years | Replace engine air cleaner filter |
| 60,000 and 120,000 miles | Change transfer case fluid (4x4) |
| 67,500 and 150,000 miles | Replace crankcase ventilation (CCV) filter (Mopar 68677813AA) |
| 97,500 miles / 78 months | Flush and replace power steering fluid |
| 100,000 miles | Replace spark plugs (mileage based only); inspect and replace PCV valve if necessary |
| 120,000 miles | Change transfer case fluid |
| 120,000 miles | Change automatic transmission fluid and filter(s) (ZF 8-speed) |
| 10 years or 150,000 miles | Flush and replace engine coolant |
| 150,000 miles / 120 months | Flush and replace engine coolant (dealer-recommended service) |
Time-Based Service
Several 2025 Ram Heavy Duty items are governed by time as well as miles, whichever comes first:
- Engine oil and filter: at least every 12 months on either engine, even at low mileage (the HEMI also caps at 350 engine hours)
- Tire rotation and CV/U-joint inspection: HEMI every 10,000 miles or 1 year; Cummins every 7,500 miles or 6 months
- Front suspension, axle and brake inspections: HEMI every 20,000 miles or 2 years; Cummins fuel filters and front suspension every 15,000 miles or 12 months, brake linings, drive belt and axles every 22,500 miles or 18 months
- Engine air filter: HEMI every 30,000 miles or 3 years; Cummins inspected every 15,000 miles and replaced by 30,000 miles or 24 months at the latest
- Cummins power steering fluid: flush and replace at 97,500 miles or 78 months
- Engine coolant: Mopar OAT coolant on both engines; HEMI at 10 years or 150,000 miles, Cummins at 150,000 miles or 120 months
- Brake fluid: the 2025 manual sets no replacement interval for the HD; DOT 3 brake fluid is inspected at every service
Engine-Specific Maintenance Details
The two engines shared by the 2025 Ram 2500 and 3500 take completely different oils. The 6.4L HEMI V8 uses SAE 0W-40 full synthetic (MS-A0921, API SP), 7.0 quarts with the Mopar 4892339BE spin-on filter, and runs on 87 octane. The 6.7L Cummins High Output uses SAE 10W-30 above 0 F or SAE 5W-40 synthetic below 0 F, meeting MS-10902 and API CK-4 (Cummins CES 20081 oils are also acceptable), 12.0 quarts with the Mopar 68677810AA (Fleetguard LF16453) filter. The HEMI carries 16 spark plugs (Mopar SP138239AC, two per cylinder) replaced at 100,000 miles; the diesel has no spark plugs. Both 8-speed automatics take Mopar ZF 8 & 9 Speed ATF per the 2025 owner's manual, and the Cummins 8AP1075 gets fresh fluid and filter(s) at 120,000 miles; no fluid change is listed for the HEMI's 8HP75. Both engines share the Mopar 68548579AA cabin filter and Mopar OAT MS.90032 coolant.
| Specification | 6.4L HEMI V8 | 6.7L Cummins High Output Turbo Diesel I6 |
|---|---|---|
| Oil Type | SAE 0W-40 full synthetic (MS-A0921, API SP) | SAE 10W-30 (above 0 F) or SAE 5W-40 synthetic (below 0 F) meeting MS-10902 and API CK-4 |
| Oil Capacity | 7.0 qt (with filter) | 12.0 qt (with filter) |
| Oil Filter | Mopar 4892339BE (spin-on) | Mopar 68677810AA (Fleetguard LF16453) |
| Engine Air Filter | — | Mopar 68645327AA (Fleetguard AF27684) |
| Cabin Air Filter | Mopar 68548579AA | Mopar 68548579AA |
| Spark Plugs | Mopar SP138239AC (x16, two per cylinder) | None (diesel; glow plugs on the 2025+ engine, not a scheduled item) |
| Spark Plug Interval | 100,000 mi | — |
| Transmission Fluid | Mopar ZF 8 & 9 Speed ATF (or equivalent) | Mopar ZF 8 & 9 Speed ATF (or equivalent) |
| Coolant | Mopar Antifreeze/Coolant 10 Year/150,000 Mile Formula OAT (MS.90032); 18.5 qt (owner's manual) / 16.6 qt (spec sheet) | Mopar Antifreeze/Coolant 10 Year/150,000 Mile Formula OAT (MS.90032); 22 qt (owner's manual) / 23.8 qt (spec sheet); flush at 150,000 mi / 120 months |
Cummins Diesel, Towing & Heavy-Duty Maintenance
The 6.7L Cummins High Output is the heart of the 2025 Ram Heavy Duty towing experience, and diesel ownership adds items a gas truck never sees. The two fuel filters (a front chassis-mounted 3-micron and a rear engine-mounted 5-micron, Mopar 68677800AA set) are replaced every 15,000 miles. The 7.5-gallon DEF tank is checked and topped off every 7,500 miles with API-certified ISO 22241 fluid. The crankcase ventilation (CCV) filter (Mopar 68677813AA) is replaced at 67,500 and 150,000 miles, the power steering fluid is flushed at 97,500 miles, and the ZF 8-speed behind the Cummins gets fresh fluid and filter(s) at 120,000 miles. Frequent trailer towing also moves front and rear axle fluid changes to the regular inspection interval on both engines and calls for HEMI transfer case fluid changes at 60,000 and 120,000 miles (the diesel 4x4 changes it there on the normal plan; every HEMI changes it at 120,000). B6 to B20 biodiesel is approved for both pickups.
- Use only diesel-spec oil meeting CES 20081 — never substitute light-duty gas-engine oil.
- Fuel filter and water separator service every 15,000 miles. Drain water separator at every fill-up if running biodiesel blends.
- DEF (Diesel Exhaust Fluid) is required — use only ISO 22241 spec fluid; avoid generic urea solutions.
- DEF tank typically lasts 15,000 miles between refills under normal driving.
- Cummins exhaust brake reduces friction brake wear on downhill descents — use it for extended Western NC descents.
- Cold-start in winter: let the Cummins warm up before high-load operation. Glow plug systems work but cold oil flows slowly.
- Towing 17,000+ lbs is heavy-duty severe-use — shorten all fluid intervals accordingly.
- Aisin transmission (HO Cummins) has its own service schedule — see service manual.
Severe & Special Operating Conditions
Stellantis defines severe operating conditions as any of the items below: dusty or off-road driving, frequent trailer towing, and police, taxi or fleet use. Most Ram Heavy Duty owners in the mountains qualify for at least one, and the 2025 manual adjusts specific items accordingly: the engine air cleaner is inspected at every oil change in dusty or off-road use, front and rear axle fluid is changed at the 20,000-mile (HEMI) or 22,500-mile (Cummins) inspection for police, taxi, fleet, off-road or frequent-towing use, and transfer case fluid is changed for the same conditions at 60,000 and 120,000 miles instead of only being inspected.
- Towing heavy loads regularly (15,000+ lbs)
- Extended idling (waiting in trailer queues, etc.) — common HD truck use
- Operating in dusty conditions or gravel forest roads
- Sustained mountain grade driving (Western NC routes)
- Frequent short trips that prevent engine warm-up
- Extreme cold weather (below 0°F) or extreme heat (above 100°F)
- Heavy stop-and-go traffic
- Off-road duty or jobsite operation
Service for 2025 Ram Heavy Duty Owners Across Western NC
Ram 2500 and 3500 owners across Western NC use these trucks for serious work: hauling materials around Brevard, towing campers and equipment to Asheville and Hendersonville, climbing mountain grades toward Waynesville, and running forest roads out of Pisgah Forest, plus heavy-duty fleet operations across the region. Mountain grade descents stress brakes. Heavy towing stresses the transmission and cooling system. Cold winter starts are exactly why the Cummins switches to 5W-40 synthetic below 0 F. Our Mopar-certified team includes diesel-trained technicians who know the next-generation 6.7L Cummins and the 6.4L HEMI inside and out.
Monthly & Semi-Annual Owner Checks
Between scheduled service visits, a few quick owner checks help catch problems before they become repairs. These take only a couple of minutes and apply to every 2025 Ram 2500 and 3500.
- Tire pressure — check before every loaded run; LT-rated HD tires have specific load-and-pressure curves.
- Engine oil level — check every fuel fill-up for Cummins; HEMI weekly.
- Coolant level — verify monthly; Cummins overheating causes major damage.
- DEF level — check at every fuel fill-up; running out of DEF will derate the truck.
- Brake fluid level — check monthly; HD braking systems benefit from inspection.
- Trailer hitch and electrical connections — inspect at each tow trip.
- Fuel water separator — drain at every fill-up if water present.
- Visual underbody check — fluid leaks, damaged exhaust components after any heavy work.
Note on Pricing: Ram Heavy Duty service pricing varies significantly between HEMI and Cummins. The diesel takes 12 quarts of CK-4 oil versus 7 quarts of 0W-40 for the HEMI, its two fuel filters are a recurring 15,000-mile item, and DEF refills add to operating cost. Heavy-tow customers should ask about severe-duty axle and transfer case service. Call (828) 492-2121 for engine-specific quotes.
Schedule Your 2025 Ram Heavy Duty Maintenance at Mahon CDJR
Mahon CDJR is your authorized Ram service center for the 2025 Ram 2500 and 3500. Our Mopar-certified team includes diesel-trained technicians for the next-generation 6.7L Cummins High Output and HD gas technicians for the 6.4L HEMI, with the correct Mopar oil, filters and fluids for each engine. Schedule online or call our service team at (828) 492-2121.
Created October 11, 2026 by MM Dealer Advocates