The Ram 2500 remains a benchmark for capability and toughness, but choosing the right engine in California requires more than just horsepower bragging rights. From navigating LA’s stop-and-go traffic to hauling up the Grapevine or towing through the Sierras, your engine choice directly affects performance, fuel economy, and long-term cost of ownership.
This guide breaks down the two primary powertrains — the 6.4L HEMI® V8 and the 6.7L Cummins® Turbo Diesel — and explains which is better suited for California’s unique terrain, emissions standards, and driving habits.
Ram 2500 Engine Options in 2025
- 6.4L HEMI® V8 (Gas) — 410 hp / 429 lb-ft of torque, paired with an 8-speed automatic. Standard on all trims.
- 6.7L Cummins® Turbo Diesel (High-Output) — 430 hp / 1,075 lb-ft of torque, new 8-speed HD TorqueFlite automatic, optional on heavy-duty trims.
Both engines meet California’s strict CARB emissions standards and feature technologies designed to balance power with environmental compliance.
Performance Across California Conditions
City Driving (Los Angeles, San Diego, Bay Area)
For daily commutes with limited towing, the HEMI V8 delivers quicker throttle response, smoother low-speed operation, and fewer emissions-related maintenance tasks. It thrives in traffic and short-trip scenarios where diesels may struggle to reach ideal operating temperatures.
Highway & Mountain Routes (I-5 Grapevine, Hwy 395, Sierra Nevada)
Drivers who frequently tow campers or trailers through steep grades will appreciate the Cummins HO Diesel. Its immense torque allows steady climbs at low RPMs, excellent exhaust braking downhill, and improved fuel efficiency on long hauls.
Coastal & Rural Areas
Along Highway 1 or rural farmland routes, both engines perform admirably, but the diesel shines for owners regularly hauling boats, RVs, or farm equipment thanks to its superior range and pulling strength.
Fuel Economy & Ownership Costs
- 6.4L HEMI V8: Averages ≈ 13–15 MPG city / 17–18 MPG highway (unladen). Lower upfront cost and simpler upkeep.
- 6.7L Cummins Diesel: ≈ 15–17 MPG city / 20–22 MPG highway. Requires DEF (Diesel Exhaust Fluid) and periodic DPF regeneration but benefits from superior towing efficiency and resale value.
In California, diesel prices often run $0.70–$1.00 higher per gallon than gasoline, but the efficiency gain under load and long-term durability can offset the difference for frequent haulers.
Emissions Compliance & Maintenance in California
California’s Air Resources Board (CARB) mandates strict emissions controls. Both engines comply, but each demands unique upkeep:
- HEMI V8: Simpler catalytic-converter system, standard smog test every 2 years (except new vehicles ≤ 6 yrs).
- Diesel Cummins: Includes DPF and SCR after-treatment requiring DEF fills and occasional regeneration cycles. Diesel smog inspections apply at registration renewal.
Comparative Use-Case Table
| Category | 6.4L HEMI V8 | 6.7L Cummins Diesel (HO) |
|---|---|---|
| Best for | City commutes, light towing, jobsite payloads | Heavy towing, long-distance hauling, mountain routes |
| Max Towing | ≈ 17,000 lb (config dependent) | ≈ 20,000 lb (config dependent) |
| Payload | Higher payload capacity thanks to lighter engine | Lower payload but greater towing torque |
| Maintenance | Oil every 6 months or 8k miles | Oil every 10–12k miles + DEF service |
Expert Recommendation for California Drivers
Choose the 6.4L HEMI V8 if your Ram 2500 is a daily driver in California traffic with occasional towing. It’s cleaner to maintain and complies easily with state smog regulations.
Choose the 6.7L Cummins Diesel (HO) if you regularly haul trailers, fifth-wheels, boats, or construction loads across the state. The new 8-speed HD transmission improves drivability while maintaining legendary Cummins torque and longevity.
Find Your Perfect Ram 2500 in California
At Simi Valley Chrysler Dodge Jeep Ram, our team serves drivers from Los Angeles to Ventura and beyond. We can help you test-drive both the HEMI and Cummins models and determine which fits your budget and lifestyle.
California & Simi Valley Maps
2350 1st Street, Simi Valley, CA 93065 | Sales: 805-387-9755
Frequently Asked Questions
Which Ram 2500 engine has the highest towing capacity?
The 6.7L Cummins Turbo Diesel High-Output offers up to 20,000 lb of towing capacity (depending on trim and axle ratio), making it California’s choice for serious towing and commercial use.
Is the gasoline HEMI V8 better for short California drives?
Yes. The HEMI V8 warms up faster and avoids diesel regeneration cycles that can be inconvenient for frequent short trips in cities like LA or San Francisco.
Does California require extra smog tests for diesel trucks?
Yes. California requires diesel vehicles to pass a biennial smog inspection after registration renewal under the Clean Truck Check program unless exempted by model year or weight.
Can I buy a Ram 2500 diesel anywhere in California?
Absolutely. All Cummins-equipped Ram 2500 models sold at California dealerships meet CARB certification standards and are 50-state legal.



