The Chevrolet Colorado Trail Boss and Z71 Can Make ZR2 Power With an Engine Tune

2023 Chevrolet Colorado trims from left to right: Colorado Z71, Colorado Trail Boss and Colorado ZR2

2023 Chevrolet Colorado trims from left to right: Colorado Z71, Colorado Trail Boss and Colorado ZR2
Photo: Chevrolet

Now that the new Chevy Colorado has been announced, it’s clear that the mid-size truck segment is having a moment. The 2023 Chevy Colorado is going to bask in the glow for a bit, before the spotlight returns to the full-size Chevy Silverado. But the new Colorado has the Silverado to thank for its four-cylinder engine, initially developed for the full-size truck and now adapted for the mid-sizer.

The powerplant has proven versatile; the new Colorado lineup will be powered by one engine with three variants. But the claimed output of the engines has such a wide range of power that it got us wondering: what’s setting the output apart? And, more importantly, if the engine is the same, what’s stopping a base Colorado WT from making the same power as a Colorado ZR2?

Image for article titled The Chevrolet Colorado Trail Boss and Z71 Can Make ZR2 Power With an Engine Tune

Photo: Chevrolet

For reference, the base engine will be standard on the Colorado WT and LT. Chevy calls it the 2.7-liter Turbo, and it makes 237 HP, 259 lb-ft. of torque. The Colorado Z71 and Trail Boss will get the 2.7-liter Turbo Plus that makes 310 HP, 390 lb-ft. of torque. And the Colorado ZR2 will have the 2.7-liter Turbo High-Output, which makes 310 HP, and 430 lb-ft. of torque. That’s full-size power!

In the mid-size Chevy Colorado, that power should be all the better. Chevy wants a balance of performance and efficiency, so all three engine variants feature two-cylinder deactivation. Indeed, the engines share features and much of the same hardware. The power differences come from tuning and engine management via software.

But it turns out the engine hardware is the same only on 2.7-liter Turbo Plus and Turbo High-Output engines. Not the base 2.7-liter Turbo, as the assistant chief engineer at Chevy, Kevin Luchansky, explained.

You might be surprised — like I was — that the engine is not only in the outgoing Chevy Silverado, but in the current Cadillac CT4-V as well.

Image for article titled The Chevrolet Colorado Trail Boss and Z71 Can Make ZR2 Power With an Engine Tune

Photo: Cadillac

The drivetrain team at Chevy wanted higher output than that of the CT4-V, which makes 325 HP and 380 lb-ft of torque. But the goal was for the Colorado to produce more power using regular fuel. The CT4-V makes more HP than the Colorado, but the car takes premium gasoline; the truck’s 2.7-liter Turbo Plus is happy with the less expensive combustible, reducing the cost of ownership.

The team then pushed the 2.7-liter Turbo Plus further. Even though the 2.7-liter High-Output makes the same HP and the same tow rating of 7,700 pounds, the torque jumped to 430 lb-ft. This tow rating is higher than the base engine’s 3,500 pounds, and the big bump comes from a third fan, which produces better “airflow through the charge air cooler.” Overall, this was the most performance the team could wring out of the engine while meeting durability standards.

An engine cutaway of the 2.7-liter turbocharged four-cylinder engine used in the 2019 Chevrolet Silverado.

An engine cutaway of the 2.7-liter turbocharged four-cylinder engine used in the 2019 Chevrolet Silverado.
Illustration: Chevrolet

As the engineer explained, not everyone needs the performance of the higher-spec engines. So they removed parts and optimized others for the Colorado WT’s lower curb weight. They removed the piston cooling jets, since the 2.7-liter Turbo engine has a much lower power density. And they optimized the catalytic converter for the lower weight of lower trims.

That means that the base Colorado WT engine won’t handle the power density of the Colorado ZR2 engine. So, it’s not just a matter of tuning or increasing power through software on the WT to get ZR2 performance. But since the two higher engines share hardware, a Z71 or Trail Boss could make ZR2 power through a chip/tune, and Chevy will sell owners an “accessory calibration” to take the 2.7-liter Turbo Plus to a 2.7-liter High-Output. Like the new Colorado itself, the price of the upgraded engine calibration is still unknown for now.

Image for article titled The Chevrolet Colorado Trail Boss and Z71 Can Make ZR2 Power With an Engine Tune

Photo: Chevrolet

#Chevrolet #Colorado #Trail #Boss #Z71 #ZR2 #Power #Engine #Tune

Leave a Comment

Your email address will not be published.