Overview & Reviews

GMC has long been a mainstay of American byways and highways. Originally used and respected by farmers, construction workers and small-business owners, GMC's hauler was a basic workhorse known for its reliability and longevity. More recent times have seen GMC's full-size truck adopt the name Sierra. And with a variety of body styles, powertrains and trim levels, the Sierra is as adept at serving as the weekday family car.

However, this is the 2500HD version we're talking about. Though "HD" has become a familiar pop-culture concept in recent years, rest assured that the HD part of GMC Sierra 2500HD does not, in fact, involve plasma or LCD TVs. In this case we're talking the old-fashioned meaning of HD: "Heavy Duty." As one of two GMC heavy-duty full-size pickups, the 2500HD is a true workhorse that adds big-league power, towing and hauling capabilities to its family-ready credentials.

Current GMC Sierra 2500HD
The GMC Sierra 2500HD is available in regular, extended or crew cab designs, with a long or short wheelbase, and with rear- or four-wheel drive. The extended and crew cab body styles are offered in four trim levels: Work Truck, SLE, SLT and top-of-the-line Denali. The regular cabin can only be had in Work Truck and SLE trims. Moving up through the ranks obviously adds more style and features, culminating in the top-shelf Denali.

Standard on all Sierra 2500HD pickups is a 6.0-liter V8 that makes 360 horsepower and 380 pound-feet of torque, paired to a six-speed automatic transmission. The burly Duramax 6.6-liter turbodiesel V8 that puts out 397 hp and 765 lb-ft of torque is optional. Its standard Allison six-speed automatic is well suited to towing and hauling large loads.

In a recent comparison test, GM's heavy-duty trucks came out on top thanks to superior all-around performance. Although multigenerational brand loyalty may dictate what heavy-duty pickup you take home, sticking with (or switching to) the GMC Sierra 2500HD would be a solid decision.

Used GMC Sierra 2500HD Models
The present-generation GMC Sierra 3500HD debuted for the 2007 model year. Originally, the 6.0-liter gasoline V8 produced 353 hp and 373 lb-ft of torque, while the 6.6-liter diesel V8 was good for 365 hp and 660 lb-ft. The gasoline engines' current output arrived for 2010.

More changes occurred for 2011 when the Sierra received an all-new frame along with new suspension components (for greater towing capacity and a smoother ride), a more potent turbodiesel engine cranking out 397 hp and 765 lb-ft (previously 365 hp and 660 lb-ft) and the debut of the ultra-plush Denali trim level.

The previous-generation Sierra 2500HD was sold from 2001-'06 and lived on one more year as the "Classic" for 2007. There was a heavy-duty package available for the light-duty Sierra 2500 in 1999 and 2000. That light-duty Sierra 2500 has been discontinued. In terms of updates, there were changes made to the exterior and interior styling for 2003, with further exterior tweaks for 2005. These trucks came in Work Truck (after '03), SL, SLE and SLT trim levels.

The standard engine was a 6.0-liter V8 that made 300 hp and 360 lb-ft of torque. There were two optional engines: an 8.1-liter gasoline V8 producing 340 hp and 455 lb-ft and a 6.6-liter turbodiesel producing 300 hp and 520 lb-ft. This diesel was upgraded in 2006 for more power and refinement and fewer emissions. It made 360 hp and a whopping 650 lb-ft of torque. These engines carried over for the Classic. A five-speed manual transmission was standard with the 6.0-liter V8, with a four-speed automatic optional. The 8.1-liter V8 and diesel engines came with either a six-speed manual or five-speed automatic (which became a six-speed for 2006).

As with the current GMC Sierra 2500HD, we were always impressed by this generation's powerful engine lineup and substantial towing and hauling abilities. It was a reasonably comfortable truck for everyday use, but don't expect the plush ride of its light-duty siblings. Any of the three available engines will provide swift acceleration and ample towing power, but the diesel V8 is probably the best choice for those who tow heavy loads -- especially the more powerful 2006 Duramax. Our principal beef concerns the shoddy interior design, materials and build quality. GMC improved it gradually during its lifespan, but it was never quite up to snuff.

The previous-generation GMC Sierra 2500 ran from 1988-'98 with a significant refresh for 1995. It was known as the Sierra 2500 Classic for 1999 and 2000. Strengths of these pickup trucks include strong, durable powertrains, while weaknesses center on sketchy build quality and materials within the cabin.

User Reviews:

• 

  Duramax and Allison are superior - 2003 GMC Sierra 2500HD
  By Jim T - January 20 - 5:53 am

  I have owned this truck since new in 2003. Only in the last several years have I used it to its full potential. I have pulled a 10,000 lb fifth wheel to Florida twice and a new 12,000 lb fifth wheel to GA last week and I averaged a little over 13 mpg. On the return trip I got over 24 mpg running at 70 mph all day. I do have a tonneau cover for the bed which might help. I first took this new truck to Ohio in 2003 and only got 22 mpg with the same configuration. I did add a K and N air induction system before my last trip but this truck pulls like a champ without any additonal brains or Banks kits. The 5 speed transmssion is smooth and I know improvements have been made in the 09s.

• 

  2500HD crew cab, SB with 8.1 v-8 - 2006 GMC Sierra 2500HD
  By happy GMC owner - December 25 - 1:50 am

  Nice truck overall. Really gets the job done. Best tow vehicle Ive ever owned. 8.1 V8 has plenty of torque. Gets better mileage than 454s Ive owned previously.

• 

  Clean GMC - 2007 GMC Sierra 2500HD
  By Jack - October 2 - 6:23 pm

  Bought the 6.0ltr WT version two weeks before leaving Maryland. Installed cruise control and hauled 5500 lbs on a 16ft tandem trailer and 1000 lbs in the bed. Averaged 16mpg on Hwy after tuning with the Diablo Predator using 87 octane gas. I have the 4:10 HD posi-lock rear. I average 12-13 mph in town. I would have liked the 6spd Allison transmission.

• 

  best one yet - 2004 GMC Sierra 2500HD
  By BIGGS - August 15 - 2:00 am

  2003,like the truck.already done ford and dodge,full power and towing is effortless

• 

  2500 HD GMC - 2005 GMC Sierra 2500HD
  By Enymoose - June 20 - 9:43 pm

  I highly recommend this version of the GMC to those who do not mind a stiff ride that will pull anything a truck is supposed to pull. The 6.0 engine coupled with the 4.10 rearends give it enough power to pull a house off of its foundation if you wanted to put it to that type of test. I put it to the test using the 4X4 at Ft. Fisher, NC in sand that others were getting stuck up in and had no problems once I dropped the air pressure down to 20 lbs per tire from the origional 60. The fishing was great also. Ive had 9 other 4X4s, between Ford and Chevys and this GMC is by far the

• 

  MY 2500 HD - 2001 GMC Sierra 2500HD
  By MY 2500 HC - May 16 - 2:00 am

  Overall Good Truck. I am impressed with the sturdiness of the truck. The 6.0L has provided plenty of power with only occasionaly towing. However, the engine began knocking for the first 5 minutes on start up at about 17000 miles. GM says its o.k. but extended the engine warranty to "make me feel better." Had to have work done on steering column as it began knocking when I hit bumps. Speaker in passenger door had to be replaced. I am now noticing some delay or slip in the transmission when the stop light turns green. A little scared where this all might lead. Dont have the Allison.

• 

  8.1L tons of gas power! - 2003 GMC Sierra 2500HD
  By black dog - May 11 - 4:50 pm

  The torque and power of the 8.1L is incredible, but be aware at the gas pump. An average of 9.1 mpg will be all youll get. Towing large campers or trailers is no trouble what-so- ever. Especially in lower range gears the 8.1L begs for more. All around I love the truck, including a great interior and stock stereo.

• 

  2008 GMC 2500 Diesel - 2008 GMC Sierra 2500HD
  By John - December 29 - 11:13 am

  I bought this truck from a local used car dealer. I drive this truck mostly through the mountains of southwestern PA hauling my travel trailer. I previously owned a 2005 F250 diesel. There is absolutely no comparison between the two trucks. This GMC outperforms the ford in every way possible. I never thought I would say this considering my grandfather, my father, and I have been ford guys our entire lives but the proof is in the way the truck drives, handles, pulls, and the reliability I have experienced with this truck. I have driven this truck for more than 15,000 miles and overall I am completely satisfied. I have to say that this is by far the best truck I ever owned.

• 

  So far, love it. - 2008 GMC Sierra 2500HD
  By Woof - December 27 - 2:56 am

  I bought my 08 SLT, Diesel on New Years eve day, 08. I have put on 17,000 miles mixed mostly highway and suburban with a good bit of weekend warrior hunting and camping trips. I commute in this baby and my combined mileage is 15.7 over the last 9 months. Thats with a cap on the back,and with 35 miles a day in hardcore SF Bay Area highway traffic hell. I dont tow but it will haul a back end load of hunting equipment, dogs and coolers full of meat. Honestly, I could use a lesser truck for most of what I do, but when I need to step up this truck takes it and keeps going. I can stick 3 dogs in the back of the cab, w. seats folded and they ride in comfort and one of them clocks in at 120lbs

• 

  Pleasantly Surprised - 2005 GMC Sierra 2500HD
  By K - September 21 - 6:43 pm

  Duramax diesel showing 22 to 23 mpg on highway. Very smooth shifting with Allison transmission (even under load). Ride is a little stiff, but expected with 2500HD. Truck is extremely capable.