How good is the GMC Sierra 2500 HD’s fuel economy for Oklahoma City drivers?
The Sierra 2500 HD has no EPA fuel-economy rating: at over 8,500 lb gross vehicle weight rating it is a heavy-duty truck, and the EPA neither tests nor publishes a figure for it. Without a rating, start with the engine you choose, gas or Duramax diesel. You can see each new Sierra HD’s price in our listings and reserve a test drive at our Broadway Extension store.
Bob Howard Buick GMC is at 13300 N Broadway Ext, Oklahoma City, OK 73114.
Keep reading below, then schedule a test drive in Oklahoma City. Bringing your own numbers to the lot settles this faster than any spec sheet.
How do the Sierra 2500 HD gas and diesel engines compare on GMC’s figures?
On GMC’s 2026 figures, the Duramax 6.6L Turbo-Diesel V8 makes 470 horsepower and 975 lb-ft of torque. Those numbers describe how the diesel pulls, not how far it goes on a tank. Put them next to the EPA ratings for GMC’s 2026 trucks, which show the mileage side of the choice.
How does Sierra 2500 HD fuel economy compare with other GMC trucks?
Because the Sierra 2500 HD has no EPA rating, the closest published figures are those for GMC’s lighter trucks. Among GMC’s 2026 trucks with published EPA figures, the Sierra 1500 2WD diesel posts the highest combined rating, at 25 mpg. Each combined number blends city and highway driving, so read it alongside both columns.
GMC’s published 2026 EPA figures, in miles per gallon:
| Model and drive | City | Highway | Combined |
|---|---|---|---|
| Canyon 2WD, gasoline | 19 | 23 | 20 |
| Canyon 4WD, gasoline | 17 | 22 | 19 |
| Sierra 1500 2WD, gasoline | 18 | 21 | 20 |
| Sierra 1500 2WD, diesel | 23 | 28 | 25 |
| Sierra 1500 4WD, diesel with Sport Mode | 22 | 26 | 24 |
The combined rating is a weighted average, with the city figure counted at 55% and the highway figure at 45% (U.S. Environmental Protection Agency, 2026). A driver who mostly runs city miles can read the city column directly. The combined number is the figure to use when the driving mixes city and highway miles about evenly.
How much can the Sierra 2500 HD and 3500 HD tow?
GMC lists the Sierra 2500 HD at up to 22,390 lbs of maximum towing. The 2500 HD AT4 and Denali are listed at 20,000 lbs maximum for conventional towing, in a 4WD Crew Cab with either the 6′ 9″ standard bed or the 8′ long bed.
For a heavier job, the Sierra HD 3500 HD is listed at up to 36,000 lbs maximum available. The 3500 HD Duramax 6.6L Regular Cab long bed 2WD dual rear wheel model is listed at 36,000 lbs, with a GCWR of 43,900 lbs and a maximum gooseneck trailer rating with the available Max Trailering Package. Check the towing figure for the exact cab, bed and drive you plan to buy.
See a new Sierra HD’s MSRP and sale price in Oklahoma City
Each new Sierra HD in our listings shows its MSRP, dealer discount, documentation fee and sale price per stock unit. Start with the MSRP, then check the discount and fee on the unit you want.
GMC’s published 2026 starting MSRP for each Sierra HD trim:
| Trim | Starting MSRP |
|---|---|
| Sierra HD Pro | $47,000 |
| Sierra HD SLE | $54,000 |
| Sierra HD SLT | $65,200 |
| Sierra HD AT4 | $72,200 |
| Sierra HD Denali | $75,200 |
| Sierra HD AT4X | $85,200 |
| Sierra HD Denali Ultimate | $94,200 |
Can you test drive a Sierra HD at Bob Howard Buick GMC in Oklahoma City?
Yes. You can reserve a test drive online or by contacting Bob Howard Buick GMC at 13300 N Broadway Ext, Oklahoma City, OK 73114. Plan your visit around our sales hours, which run Monday to Saturday, 8:30 AM to 9:00 PM. We are closed Sunday.
FAQ
What should I compare when choosing between a gas and a diesel Sierra 2500 HD?
Start with the engine’s output and the trim’s price. GMC’s published 2026 figures give the Duramax 6.6L Turbo-Diesel V8 470 horsepower and 975 lb-ft of torque. The Sierra HD Pro is listed at a starting MSRP of $47,000, and the Denali Ultimate at $94,200.
What warranty comes with a new Sierra 2500 HD?
GMC’s published 2026 terms give the Sierra HD a basic warranty of 3 years or 36,000 miles, whichever comes first. The powertrain warranty is typically 5 years or 60,000 miles, whichever comes first, though other durations are available.
Can I get a value for my trade-in online before I visit?
Yes. Our online trade tool takes your license plate, VIN or make and model, and it returns an instant offer. The trade-in offer amount can be entered into the payment calculator, and trade-in customers can visit with or without an appointment.
Can I apply for financing online for a Sierra HD?
Yes. A secure finance application can be completed online at Bob Howard Buick GMC. Our payment calculator is on the site too.
Does Bob Howard Buick GMC lease new GMC trucks?
Yes. We offer new Buick and GMC leases alongside new and pre-owned financing. A leased Buick GMC vehicle can be bought out at any time during the lease, and our sales specials rotate through new Buick and GMC offers.
Can I book service for my Sierra online?
Yes. Our site offers service scheduling. Parts can be ordered online for pickup, and the store calls when the order is ready. Complimentary snacks, drinks and Wi-Fi are available while customers wait.
Can I shop for a Sierra HD in Spanish?
Yes. Our staff can help customers in Spanish at 13300 N Broadway Ext, Oklahoma City, OK 73114. Sales hours are Monday to Saturday, 8:30 AM to 9:00 PM, and we are closed Sunday.
Why Oklahoma City truck buyers choose Bob Howard Buick GMC
Our Google record, as of October 2026, is 4.4 stars across 3,983 reviews, and 79% of them are five-star (Google, 2026). Two July 2026 reviews name the people who helped. In a July 2026 Google review, Kailyn R. wrote: “We had a great experience at Bob Howard’s. Wayne our sales professional was very good and patient during our experience. We found the perfect vehicle. I couldn’t recommend them enough.” In a July 2026 Google review, Madeline M. wrote: “Michael Griggs is the best salesmen I have ever worked with! Thanks Mike At Bob Howard!”
At Bob Howard Buick GMC, we sell new Buick and GMC models, including the Canyon, Sierra 1500, Sierra HD and Sierra EV. Our Buick and GMC Certified Pre-Owned vehicles come with a 172-point inspection by factory-trained technicians, an extended powertrain limited warranty and a bumper-to-bumper limited warranty.
If you want a Sierra HD in Oklahoma City, start by reserving a test drive at 13300 N Broadway Ext, Oklahoma City, OK 73114, online or by contacting Bob Howard Buick GMC.
Bob Howard Buick GMC answers this question against the specific vehicle in front of you rather than the model in general. Value your trade and get pre-approved online, then see us at our Oklahoma City showroom, or call (405) 928-0697.
Disclaimer: Vehicle features, specifications, pricing, options, and availability may vary based on production timelines and dealership inventory; images are for illustrative purposes only. Starting MSRP figures are national and exclude destination freight charges, tax, title, license, and dealer fees. Standard and available equipment varies by trim, configuration, and model year; confirm the specification of the individual vehicle before purchase. Maximum towing and payload ratings depend on cab, bed, drivetrain, and equipment configuration; see the vehicle’s Owner’s Manual and trailering guide for limits. Electric range and charging times vary with battery, configuration, temperature, terrain, load, and driving habits. Safety or driver assistance features are no substitute for the driver’s responsibility to operate the vehicle in a safe manner. Financing and pre-approval are subject to credit approval. Contact Bob Howard Buick GMC for complete details regarding current vehicle inventory, pricing, and equipment.
