The powertrain engineers at General Motors (GM) - Get Report are some of the world's most talented. You might recall that they and Boeing (BA) - Get Report co-developed an electric car called the Lunar Rover for NASA's Apollo moon missions some 50 years ago. Think about that for a minute -- CEO Elon Musk of Tesla (TSLA) - Get Report was born just weeks before a GM-designed electric car was driving around on the moon in 1971.

Back here on Mother Earth, GM's engineers recently faced another design challenge -- how to improve a large pickup truck's fuel economy by keeping its weight down. After all, a pickup truck's worst enemy is weight.

A truck is supposed to haul and tow as many thousands of pounds as possible, but if its engine or surrounding components weight a lot, that takes away from the vehicle's towing ability. So, automakers must avoid embedded weight at all cost.

Ford (F) - Get Report went after this problem a few years ago with an all-aluminum body that shaved up to 700 pounds per truck. And GM likewise cut some 450 pounds of body weight off of its all-new 2019 Chevrolet Silverado 1500 full-sized pickup.

But GM also had an additional weight-reduction strategy up its sleeve -- cut the weight of the Silverado's engine itself. Specifically, GM outfitted some versions of the Silverado 1500 with an engine that has only four cylinders in an inline formation, saving lots of weight compared to what a V-6, V-8 or a straight-six-cylinder engine clocks in at.

Now, there's been no shortage of pickups with four-cylinder engines in years gone by from GM, Ford, Toyota (THC) - Get Report , Nissan (NSANY) and others. But those only came in midsize trucks rather than full-size ones. The 2020 Silverado 1500 is the first major full-sized truck that's powered by a four-cylinder gas engine.

These straight-four-cylinder engines are only 2.7 liters -- but with a whopping 310 horsepower, who needs a 5.4-liter V-8? Besides, the Silverado's straight-four engine saves 80 pounds compared to a 4.3-liter V-6.

The four-cylinder Silverado 1500 starts at around $40,000, a reasonably equipped version will set you back about $50,000. Here's what I found when I recently tested a four-cylinder Silverado 4WD LT double-cab (list price $49,365 as equipped):

Great Mileage for a Big Truck

The Silverado 1500 that I test-drove delivered good fuel economy without feeling like I'd given up the power that a larger V-6 or V-8 engine offers. In fact, my test model did so even though it came with all-terrain tires that were neither optimized for highway driving nor for any form of street fuel economy.

Still, I achieved about 18 miles per gallon fuel efficiency in city driving and roughly 23 mpg on the freeway at around 65 miles per hour. Those are excellent real-world results for such a giant truck.

The 2019 Chevrolet Silverado comes with a generous interior.

And mind you, this wasn't a diesel truck -- just a "regular" gas-powered one. That means the engine doesn't cost a fortune extra up-front (as diesels typically do), nor does the engine require any special maintenance.

As a result, the Silverado's total economic advantages are even more favorable than my combined highway/city fuel economy of 21 mpg suggests.

Few Downsides to the Improved Fuel Efficiency

This truck didn't require any babying in order to deliver such respectable miles per gallon. Rather, it had as much power as anyone could ever desire unless you need to tow more than 7,000 pounds (at which point you'd go with the model's six- or eight-cylinder options).

Are there any downsides to this straight-four-cylinder engine? The only thing I found was its lack of classic V-8 sound, which, frankly, isn't a big deal to most people any more. The straight-four's sound isn't bad even if it's not a V-8 engine's lovely rumble.

Speaking of the straight-four vs. a V-8, look under the hood and what do you see? A tiny engine block so small that it almost disappears under the hood, as if it were a miniature component. You can almost see the 380 pounds or so in weight savings.

The 2019 Silverado's available inline-four-cylinder engine puts out amazing power for such a small device.

The Bottom Line

If you're in the market for a full-size pickup truck where you can sit three people up front, look no further than the four-cylinder GM Silverado.

Yes, Ford and Ram full-size trucks are also great and have various advantages of their own. For example, Fords offer outstanding seats and a superb seating position. Similarly, Rams boast the best rear suspension, the first hybrid V-6 and V-8 gas engines produced in high volume and by far the most beautiful interiors of any vehicle in the segment.

However, GM has broken new ground with the Silverado. Its engine offers low weight and outstanding fuel economy, all without sacrificing on engine power. As long as you don't need to tow more than 7,000 pounds or haul more than 2,100 pounds of on-board payload, this model is for you.

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At the time of publication, Wahlman was short TSLA. However, positions can change at any time. The author also regularly attends press conferences, new-vehicle launches and the equivalent hosted by most major automakers. Additionally, GM provided the vehicle for this review.