by Chevy Man on Mar 2, 2010 Vehicle: 2003 GMC Sierra 2500HD 4dr Crew Cab SLE 4WD SB (6.0L 8cyl 4A)
I've had my 2500HD for just under a year now and I LOVE it. The only problem I really have is its fuel economy. I average around 14 mpg, but where it lacks fuel economy it makes up for it in power. I haul around a skidsteer on a 14 ft open trailer. The skidsteer weighs more then my truck but still no problems pulling it. The fuel economy doesn't really change weather your hauling or not. I just purchased an SLR performance chip that should do the trick. This truck is perfect for anyone with the money to pay for gas.
by Jim T on Oct 29, 2009 Vehicle: 2003 GMC Sierra 2500HD 4dr Extended Cab SLE 4WD SB (6.0L 8cyl 4A)
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 09's.
by black dog on Aug 28, 2005 Vehicle: 2003 GMC Sierra 2500HD 4dr Crew Cab SLE 4WD SB (6.0L 8cyl 4A)
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 you'll 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.
by Ted Sparling on Feb 24, 2005 Vehicle: 2003 GMC Sierra 2500HD 4dr Extended Cab SLE 4WD SB (6.0L 8cyl 4A)
The Isuzu engine is the best part of this truck, along with the Allison tranny. The worst part has been all the GM stuff. Everything from numerous AC problems to leaks, memory features deleting themselves, multiple transfer case problems for auto 4WD, and leaking fuel injectors. If it were not for the dealership's attitude and incompetance i would buy again.
The Sierra gets a revised look this year that includes a new front fascia, revised side moldings and optional multifunction, fold-away mirrors. On the inside, GMC has added new seats, a more comprehensive driver information center, a redesigned instrument panel and optional dual-zone climate control and satellite steering wheel controls. On the hardware side, the standard 6.0-liter V8 gets electronic throttle control as well as the ability to run exclusively on Compressed Natural Gas (CNG) or a mix of CNG and gasoline. Other upgrades include an improved Insta-Trac part-time four-wheel drive system for reduced service costs, a more efficient starter for the 8.1-liter V8 and a revised headlight switch that allows drivers to turn off the daytime running lamps.