6.7 Cummins Oil Capacity Guide: Exact Specs You Need
By the CarsDailyHub Editorial Team | Automotive writers; every article fact-checked against Cummins and RAM service documentation | Updated June 2026
Quick Answer: The 6.7L Cummins Turbo Diesel engine (2010+) holds approximately 12 quarts (11.4 liters) of oil with a filter change. The correct oil is 5W-40 full synthetic diesel oil meeting API CK-4 or ACEA E7/E9 specifications. The oil filter is a Fleetguard Stratapore or Mopar equivalent. Change interval: 15,000 miles (24,000 km) or 12 months for normal service, 7,500 miles (12,000 km) for severe service.
This guide covers oil capacity and specifications for the 6.7L Cummins Turbo Diesel engine found in RAM 2500/3500 trucks (2010-2024). Last reviewed: June 2026.
Table of Contents
- 6.7 Cummins Oil Capacity Quick Reference
- Correct Oil Type and Specification
- Recommended Oil Brands
- Oil Change Interval
- Step-by-Step Oil Change Guide
- Signs Your 6.7 Cummins Needs an Oil Change
- What Happens If You Use the Wrong Oil?
- Cost Breakdown
- Frequently Asked Questions
- Sources & References
6.7 Cummins Oil Capacity Quick Reference
| Specification | Value |
|---|---|
| Oil capacity (with filter) | 12 quarts (11.4 liters) |
| Oil capacity (without filter change) | 11.5 quarts (10.9 liters) |
| Recommended viscosity | 5W-40 full synthetic |
| Alternative viscosity (hot climate) | 15W-40 full synthetic |
| Oil specification | API CK-4 or ACEA E7/E9 |
| Oil filter | Fleetguard LF16035 or Mopar 68249408AB |
| Drain plug size | 13mm or 14mm (varies by year) |
| Change interval (normal) | 15,000 miles / 12 months |
| Change interval (severe) | 7,500 miles / 6 months |
Correct Oil Type and Specification
The 6.7L Cummins requires diesel-specific oil that meets one of these specifications:
| Specification | Description | Acceptable? |
|---|---|---|
| API CK-4 | Current diesel oil standard | Yes, preferred |
| API CJ-4 | Previous diesel standard | Yes, acceptable |
| ACEA E7/E9 | European diesel standard | Yes, acceptable |
| API SN (gasoline) | Gasoline engine oil | No, do not use |
Use 5W-40 full synthetic for most conditions. In consistently hot climates (above 40°C / 104°F), 15W-40 full synthetic is acceptable. Do not use gasoline engine oil (API SN) in a Cummins diesel. Gasoline oil lacks the detergent and dispersant additives that diesel engines need to handle soot.
Recommended Oil Brands
| Brand | Product | Price Range | Notes |
|---|---|---|---|
| Shell Rotella T6 | 5W-40 Full Synthetic | $22-28/gal | Most popular, excellent value |
| Valvoline Premium Blue | 5W-40 Full Synthetic | $25-30/gal | Cummins-approved, good quality |
| Mobil 1 Turbo Diesel | 5W-40 Full Synthetic | $26-32/gal | Excellent cold-start protection |
| Chevron Delo 400 | 5W-40 or 15W-40 | $20-26/gal | Good value, heavy-duty |
| Royal Purple | 5W-40 Max Diesel | $30-38/gal | Premium, high performance |
Oil filter: Use a Fleetguard Stratapore (LF16035) or Mopar (68249408AB). Do not use cheap aftermarket filters. The 6.7 Cummins produces significant soot, and a high-quality filter is essential.
Oil Change Interval
| Driving Condition | Interval | Examples |
|---|---|---|
| Normal (highway, moderate temps) | 15,000 mi / 12 mo | Highway driving, light towing |
| Severe (towing, city, extreme temps) | 7,500 mi / 6 mo | Heavy towing, city driving, extreme heat/cold |
| Heavy towing (max load) | 5,000 mi / 6 mo | Max trailer weight, construction |
| Biodiesel (B20) | 7,500 mi / 6 mo | Biodiesel degrades oil faster |
Most 6.7 Cummins owners should use the severe service interval (7,500 miles / 6 months) because diesel trucks are typically used for towing, hauling, or city driving.
Step-by-Step Oil Change Guide
Tools and Materials
| Item | Purpose | Cost |
|---|---|---|
| 12 quarts 5W-40 full synthetic | Engine oil | $65-90 |
| Oil filter (Fleetguard LF16035) | Filter | $15-25 |
| 13mm or 14mm socket | Drain plug | $10 |
| Oil filter wrench | Remove filter | $5-10 |
| Funnel | Pour oil | $3 |
| Drain pan (large) | Catch 12 quarts | $15-20 |
Steps
- Warm the engine. Drive for 15 minutes so the oil flows freely.
- Park on level ground. The RAM 2500/3500 is high enough that you may not need to jack it up.
- Locate the drain plug on the oil pan. Place a large drain pan underneath (needs to hold 12+ quarts).
- Remove the drain plug. Let the oil drain for 10-15 minutes.
- Remove the oil filter. It is located on the driver’s side of the engine, near the top. Use an oil filter wrench if needed.
- Prepare the new filter. Apply a thin film of clean oil to the new filter’s rubber gasket.
- Install the new filter. Hand-tighten until the gasket contacts, then 3/4 turn more.
- Reinstall the drain plug with a new crush washer. Torque to spec (usually 20-30 ft-lbs).
- Add 12 quarts of 5W-40 through the oil filler cap on top of the engine.
- Check the level. Wait 2 minutes, pull the dipstick, and verify the level is between MIN and MAX.
- Start the engine. Let it idle for 30 seconds and check for leaks.
- Reset the oil life monitor in the dashboard menu.
- Dispose of old oil at any auto parts store or recycling center.
Time: 30-45 minutes. Difficulty: Beginner to Intermediate.
Signs Your 6.7 Cummins Needs an Oil Change
- Oil life monitor reads 5% or less
- Dark, gritty oil on the dipstick (diesel oil darkens faster than gasoline oil, but should not be thick or sludgy)
- Engine is louder than normal (injector tick or valve noise increases with degraded oil)
- Black smoke from exhaust (can indicate oil degradation or other issues)
- Oil pressure gauge reads lower than normal (at idle, should be 10-25 psi; at highway speed, 30-60 psi)
- It has been over 12 months since the last change
What Happens If You Use the Wrong Oil?
| Wrong Oil | Consequence | Severity |
|---|---|---|
| Gasoline oil (API SN) in diesel | Soot overload, sludge, DPF clogging | Critical |
| Wrong viscosity (too thick) | Poor cold starts, reduced fuel economy | Medium |
| Wrong viscosity (too thin) | Low oil pressure, bearing wear | High |
| Conventional instead of synthetic | Faster breakdown, shorter change interval | Medium |
| Cheap aftermarket filter | Poor filtration, engine wear | High |
| Overfilling | Foaming, seal damage, crankcase pressurization | High |
Cost Breakdown
| Service | DIY Cost | Shop Cost (US avg) | Time |
|---|---|---|---|
| Oil change (12 qt + filter) | $80-115 (oil + filter) | $150-250 | 30-45 min |
| Oil + filter only (no labor) | $80-115 | $80-115 | – |
| Oil analysis (optional) | $25-30 (kit) | $30-50 | 5 min + lab time |
DIY saves $70-135 per oil change. With the severe service interval (7,500 miles), you may change oil 2-4 times per year, saving $140-540 annually.
Frequently Asked Questions
Q: How much oil does a 6.7 Cummins take?
A: The 6.7L Cummins Turbo Diesel holds approximately 12 quarts (11.4 liters) of oil with a filter change. Without changing the filter, it holds about 11.5 quarts. Always buy 12 quarts and check the dipstick after filling, as the exact amount can vary slightly by model year and filter type.
Q: What oil does a 6.7 Cummins use?
A: Use 5W-40 full synthetic diesel oil meeting API CK-4 or ACEA E7/E9 specifications. Shell Rotella T6 5W-40 is the most popular choice. In consistently hot climates, 15W-40 full synthetic is acceptable. Do not use gasoline engine oil (API SN). Diesel oil has specific detergent and dispersant additives to handle soot that gasoline oil lacks.
Q: How often should I change the oil in my 6.7 Cummins?
A: For normal driving, every 15,000 miles or 12 months. For severe service (towing, city driving, extreme temperatures, biodiesel), every 7,500 miles or 6 months. Most 6.7 Cummins owners should use the severe service interval because diesel trucks are typically used for towing and hauling.
Q: What oil filter should I use for my 6.7 Cummins?
A: Use a Fleetguard Stratapore LF16035 or Mopar 68249408AB. These are the OEM-specified filters with the correct filtration rating for the 6.7 Cummins. Do not use cheap aftermarket filters. The 6.7 Cummins produces significant soot, and a high-quality filter is essential for engine longevity.
Q: Can I use 15W-40 instead of 5W-40 in my 6.7 Cummins?
A: Yes, in consistently hot climates (above 40°C / 104°F). 15W-40 provides better high-temperature protection but flows slower at cold start. If you live in a climate that drops below freezing, use 5W-40 for better cold-start protection. If you live in a hot climate year-round, 15W-40 is fine.
Q: How much does a 6.7 Cummins oil change cost?
A: DIY costs $80-115 for 12 quarts of 5W-40 full synthetic oil plus a Fleetguard filter. At a shop, the total cost is $150-250. DIY saves $70-135 per oil change. With the severe service interval (7,500 miles), you may change oil 2-4 times per year, saving $140-540 annually.
Sources & References
- Cummins Inc. – 6.7L Turbo Diesel Engine Service Manual
- RAM Trucks – Owner’s Manual for 2500/3500 with 6.7 Cummins
- API (American Petroleum Institute) – CK-4 diesel oil specification
- Fleetguard – LF16035 filter specifications
- Shell – Rotella T6 5W-40 product data sheet
- RepairPal – Average oil change cost estimates for RAM 2500/3500
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– Engine Oil & Fluids: Complete Guide
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– Engine Oil Capacity Chart for All Vehicles in Australia
– Overdue Oil Change Symptoms: What to Watch For
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