6.2L GM/Detroit Diesel

6.2L Diesel Specs, History, & Information

General Motors introduced the 6.2L Diesel for the 1982 model year. GM felt the need to add a fuel efficient alternative to their gas guzzling V-8's to the Chevrolet and GMC pickup brands. The resulting engine, manufactured by Detroit Diesel (a division of General Motors at the time), was not intended to be the workhorse of their engine lineup, but rather an economical alternative. If torque or towing was a primary concern, GMC/Chevrolet pickups could be ordered with a burly big block. The naturally aspirated 6.2L lived up to its expectations as a fuel sipper.

Farmers could haul hay and tools around the ranch without tearing deep into their pockets, and make it to the feed store on a budget. While the 6.2 diesel was no heavy hauler, it certainly appealed to a particular niche market. In the long run, the 6.2 would prove to have some reliability concerns including reoccurring overheating issues, cracked engine blocks, and failures of the harmonic balancer, crankshaft, and flywheel (the three of which are often related to one another). The 6.2L shares the same bellhousing bolt patterns and motor mounts as all GM V-8 gas engines, simplifying production and integration of the diesel power plant into C/K series pickups.

6.2L GM Diesel Specs


Detroit Diesel (a division of GM at the time)

Production Years:

1982 - 1993


GM/Chevrolet C/K trucks, Hummer H1, Jimmy, Suburban


90° V-8

Block/Head Material:

Cast iron engine block, cast iron cylinder heads


379 cubic inches, 6.2 liters

Firing Order:


Cylinder Numbers:

6.2L GM, Detroit diesel cylinder numbers




3.98 inches


3.82 inches


• IDI (indirect injection)
• Mechanical injectors, Stanadyne DB-2 rotary injection pump


Naturally aspirated, non- turbo

Nominal Dimensions:







Engine Oil Capacity:

7 qts w/ filter

Dry Weight:

Approx 750 lbs

Normal Operating Temp:

190 - 230° F

Idle Speed:

650 rpm (+- 25 rpm)

Max Engine Speed:

3,600 rpm (4,000 w/ no load)

Peak Horsepower:

• 130 HP @ 3,600 rpm (introductory)
• 143 HP @ 3,600 rpm (peak)

Peak Torque:

• 240 lb-ft. @ 2,000 rpm (introductory)
• 257 lb-ft. @ 2,000 rpm (peak)


The 6.2L became available following the retirement of the infamous 5.7L Olds diesel. It was available in 1/2 ton as well as 3/4 and 1 ton model pickups, which is unique to GMC/Chevrolet because Ford and Dodge never offered diesels in their 1/2 ton pickups when they entered the diesel sector in 1983 and 1989, respectively. At an option of less than $1,500 and capable of surpassing some of GM's V-6 gas engines in fuel economy, the 6.2 diesel was an attractive offer. The engine's were Federally rated at up to 23 mpg combined and GM estimated up to 31 mpg on the highway. GM secured a government contract and provided 6.2L diesel engines and trucks to the United States Army in mass quantities, many of which can still be affordable purchased at government auctions. Despite some of the problems that plagued the 6.2L diesel in the long run, the engine ultimately achieved what GM/Detroit had set forth to do and paved the way for future endeavors in the diesel sector.