About 160 horsepower (SAE net) from the 4.3-liter V6 in the 1991 S-10.
Engine and horsepower numbers
The 1991 S-10 used GM's 4.3-liter V6 (262 cubic inches) as the top engine option. For that year, GM typically listed around 160 horsepower under SAE net ratings, with torque near 235 lb-ft. Some older brochures and promotional materials cited roughly 165 horsepower under gross (pre-emission) ratings. The exact figure you encounter can depend on the source and whether the rating is net or gross horsepower.
SAE net vs gross ratings
Since the adoption of SAE net horsepower ratings, official figures reflect what the engine produced under those test conditions. In the early 1990s, some literature still used gross horsepower figures, which are higher because they don’t account for accessories and emissions equipment. For the 1991 S-10 4.3, the commonly cited figure remains around 160 hp SAE net, with occasional references to ~165 hp in older or non-net specifications.
Performance context
With roughly 235 lb-ft of torque, the 4.3 V6 offered solid mid-range performance for a compact pickup of its era. The power helped with towing light loads and maintaining comfortable acceleration in daily driving, especially when paired with the available automatic or manual transmissions of the time.
What happened after 1991
GM later upgraded the 4.3-liter V6 to the Vortec 4300 in the mid-1990s, which increased horsepower to about 190 hp and torque to roughly 260-270 lb-ft. This newer engine appeared in later S-10 models (as well as Blazer/Jimmy platforms), reflecting a clear step up in performance from the 1991 configuration.
Summary
The 1991 Chevy S-10 with the 4.3-liter V6 delivered approximately 160 hp (SAE net) and around 235 lb-ft of torque. Some older literature cited slightly higher gross horsepower figures, but the standard, widely accepted rating for that year is ~160 hp net. In later years, the same engine family evolved to deliver around 190 hp with the Vortec 4300 upgrade.