1986 GMC K15 Specs

by Tim McQuade

The designation "K15" was a model number for a truck manufactured by GMC. The "K" signifies that the truck is four-wheel drive (a "C" indicated two-wheel drive). In 1986, GMC also offered the Jimmy, which used the design and components of the K15, but it was an SUV. The GMC C/K truck line has been in production since the 1960s, however, GMC phased out the "C/K" nomenclature around 2000. Today, the truck is known as the Sierra.

Engine Specifications

The standard engine on the 1986 K15 was the 90-degree, V-6 Vortec engine. The 4.3-liter engine could produce a power output of 155 horsepower at 4,000 rpm and had a max torque potential of 230 foot-pounds at 2,400 rpm. The piston compression ratio was 9.3-to-1 and the piston bore and stroke measured 4 inches by 3.48 inches. The fuel system used a four-barreled carburetor. The combined gas mileage measured approximately 15 mpg.

For added power, a 5-liter, V-8 engine design was also available. This engine was common on other GMC and Chevrolet vehicles, such as the GMC Jimmy and Suburban. This engine had a piston bore and stroke of 3.73 inches by 3.47 inches and a compression ratio of 9.2 to 1. Maximum power output of the engine was 160 horsepower at 4,400 rpm and torque output was 240 foot-pounds at 3,200 rpm. Combined gas mileage measured approximately 12 mpg.

A 6.2-liter, V-8, Detroit Diesel engine was also optional in 1986. It had a bore and stroke of 3.98 inches by 3.8 inches and a compression ratio of 21.5 to 1. It also use an overhead valve design and had two valves per cylinder, totaling 16 valves. The 6.2 diesel engine had a power output of 130 horsepower at 3,600 rpm and a torque output of 240 foot-pounds at 2,000 rpm. The engine block and head were made of cast iron and it used an indirect fuel injection system. Combined fuel economy measured 17 mpg.

Finally, a 7.4-liter, gasoline, V-8 engine was also available. This was one of the largest engines used by GMC at the time. It had a bore and stroke of 4 inches by 3.48 inches and a compression ratio of 8.3 to 1. Its total power output was 185 horsepower at 4,000 rpm and a total torque capability measured 285 foot-pounds at 2,400 rpm.


The K15 had a length of approximately 184 inches, a width of 80 inches and a height of 74 inches. The wheelbase measured 117.5 inches and the minimum ground clearance was 6.9 inches. Total vehicle weight was around 6,000 lbs.


The previous year introduced a redesigned grille, as well as a hydraulic clutch. Available transmissions were a three-speed automatic, a four-speed manual and a four-speed automatic. Three trim levels were available: the Sierra, the Sierra Grande and the Sierra Classic. The Sierra Grande featured chrome details, while the Sierra Classic had power windows and power locks.

About the Author

Tim McQuade began writing in 1999. He has worked for two newspapers, including "The Ithaca Times," and has had a short story published. McQuade received a Bachelor of Arts in writing from Ithaca College.

More Articles