OK. OK. I know most people aren’t buying trucks to be earth-friendly and fuel-efficient, but it certainly plays a part. What’s odd is that with the growing efficiency of smaller four-cylinder and V6 engines, many trucks are still dedicated to giant V8s with an abysmal fuel economy. While the 2021 Toyota Tundra 4WD is technically the worst in fuel efficiency for a factory-stock pickup, the 2021 Chevy Silverado is nipping at its heels. 

2021 Chevy Silverado: Runner up

We should mention, according to Car and Driver, the Chevy Silverado routinely outsells its mechanical GM twin, the GMC Siera. The Siera and Silverado have the same engine, chassis, and transmission. For the sake of brevity, we will focus on the Silverado even though they have the same fuel economy. 

There are several engine and transmission options, but the big 355-hp 5.3-liter V8 paired with a dated six-speed automatic is the heavyweight drinker in question. In the Trailboss configuration (V8 with the six-speed), the thirsty Chevy clocks only 16 mpg. If paired with more modern and efficient transmissions like the eight-speed or ten-speed automatic, the Silverado can clear 18 and 19 mpg, respectively. The fact that the six-speed automatic is still offered shows Chevy’s hopes for the worst-fuel-economy belt. 

Silverado specs

There are plenty of other options for the Chevy Silverado. The headliner for the powertrain options is the mondo 420 hp 6.2-liter V8 that, due to an updated transmission, is both quicker and more fuel-efficient than the 5.3-liter with the six-speed transmission. 

The show stopper for most new trucks, the Silverado included, is implementing the turbocharged four-cylinder. The towing capacity of the mini marvel has grown to 9500 lbs. The tailgate Multi-Flex tailgate redesign offers a six-way Swiss-army-knife-like functionality. 

2021 Toyota Tundra 4×4: Winner 

In this fuel-economy race to the bottom, the 2021 Toyota Tundra has it in the bag, but just barely. Many people who buy Toyotas love them. They are good looking, strong, and reliable. However, the sales numbers show that the Tundra has had its struggles compared to other full-size trucks. Just about every major mark (GMC, Ford, Ram, and Chevy) has consistently outsold the Tundra 4×4. Maybe the title of the least fuel-efficient factory-stock pickup had something to do with it?

The Tundra is coming in hot with the 5.7-liter V8 paired with, yet again, a six-speed automatic transmission making 381 hp. I assume, due to weight increase, the 4×4 version gets a tragic 14 mpg, while the two-wheel-drive verison squeaks a slightly-better 15 mpg. Car and Driver says that even the Nissan Titan, which sports a massive V8, gets better mpg but sells even fewer units than the Tundra. I guess even with rough fuel-economy, the Tundra is still a Toyota and people like that. 

Toyota Tundra 4×4 specs

The Tundra has not gotten great reviews. Car and Driver says the Tundra suffers from a sloppy transmission, clumsiness at highway speeds, and, of course, terrible fuel economy. The big V8 can tow 10,500, which may sound decent until we recall how far the turbocharged four-cylinders and V6s have come with towing capacity. 

Toyota still shines with the off-road-focused TRD models. Suspension, power, and trans works well within the TRD sector, but Toyota still suffers from feeling outdated inside. Car and Driver goes so far as to say that many aspects of the interior feel outdated and all together obsolete. 

The fuel economy difference between the two is so minuscule that you really have to choose based on which you like more. That being said, the list of reasons to buy a big V8 truck is shrinking to nearly zero.