Some variants of the 2021 Chevrolet Silverado 1500 come with a choice of the two least expensive gasoline engines in the range. The Chevy Silverado engines in question are GM’s turbocharged 2.7L I4 L3B and the older, naturally aspirated 4.3L V6 LV3. Since the decision to buy one or the other has little effect on purchase price, buyers often find themselves wondering which engine to pick, so we thought it would be worth comparing the two.
First, some background. The 4.3L V6 LV3 is the older of these Silverado engines, having made its debut in the 2014 Chevy Silverado 1500 and GMC Sierra 1500. It is part of GM’s fifth generation Small Block family, known as EcoTec3, and is closely related to the 5.3L V8 L83 and the 6.2L V8 L86. Its design calls for two overhead valves (OHV) per cylinder operated via pushrods by a single camshaft in the center of the Vee.
By comparison, The 2.7L I4 L3B was initially introduced in the 2019 Chevrolet Silverado 1500 and the 2019 GMC Sierra 1500 and is significantly more modern. It has four valves per cylinder, and they are operated more directly than in the V6 by double overhead camshafts (DOHC). The dual-volute turbocharger spools up quickly and is therefore particularly effective at low engine speeds, with minimal turbo lag. As with all compressors, it also helps to compensate for thin air at high altitudes.
Both of these Silverado engines feature continuously variable valve timing and Active Fuel Management (AFM), which shuts down cylinders to improve fuel economy when only small amounts of power are required. The 2.7L I4 L3B also has variable valve lift, which improves its efficiency still further over a range of engine speeds and is responsible for the engine producing peak torque all the way from 1,500 to 4,000 rpm. The combination of AFM, variable valve timing and variable valve lift has led GM to give the valvetrain system the name TriPower.
A combination of all the above and the fact that the 2.7L I4 L3B is lighter than the 4.3L V6 LB3 gives the four-cylinder unit a big advantage in this battle of entry-level Silverado engines.
|21MY 2.7L I4 L3B Turbo
|21MY 4.3L LV3 V6
|+/- 2.7L I4 Turbo
|+25 hp or + 9%
|+43 lb-ft or +14%
|+4 / +2 / +4 or 25%
|+1,700 pounds or +22%
|+30 pounds or +1.5%
|1 second faster
In fact, the boosted four banger wins on many levels including horsepower (up 9 percent), torque (up 14 percent) and fuel economy (up 25 percent). It also delivers 22 percent greater maximum towing and slightly higher (1.5 percent) payload. And, as GM Authority recently reported, it also delivers a 0-60 time that’s 1 second faster.
GM notes that the 2.7L I4 L3B is torquier than two leading competitor engines – Ford 3.3L V6 (by 31 percent) and the RAM 3.6L V6 mild hybrid (by 29 percent). GM also points out that its four-cylinder turbo has similar fuel economy figures to the RAM while beating the Ford in this metric.
So when it comes to Silverado engines, it’s very clear that the 2.7-liter four-cylinder turbo outperforms the more traditional V6 in almost every area.