The new 2021 Ford F-150 has a host of changes including a new hybrid system, on-board generator (no, it’s not just an inverter) and, what seemed to be, only one change to the 5.0-liter V-8 Coyote engine, which is a slight bump in horsepower and torque.
Yet, that’s not all that’s changing.
Ford’s V-8 option for the 2021 F-150 will join GM and Ram in utilizing a cylinder deactivation system. This information was missed in our initial write-up and, frankly, after scouring the press materials, we still missed it, so we followed up with Ford to confirm.
“The 5.0-liter V-8 gets a bump of 5 horsepower and 10 pound-feet of torque, to 400 horsepower and 410 pound-feet,” said Dawn McKenzie, Ford Truck Communications Manager. “We’ve also added a variable displacement cylinder deactivation function to the 5.0-liter, helping fuel economy by reducing the number of cylinders receiving fuel during lower speeds and under light loads.”
Unlike GM’s system (more on that later), Ford’s cylinder deactivation will be a simple 8 cylinder to 4 cylinder setup.
This has been a controversial engine technology for some consumers with many GM owners complaining of oil usage issues. Others consider it a waste of time and, instead, purchase cylinder deactivation override products.
However, this seems to be a sign of the times, and cylinder deactivation is likely going to be in all V-8 engines eventually as the new Safer Affordable Fuel-Efficient (SAFE) Vehicles document, which is part of the 2020 Corporate Average Fuel Economy (CAFE) rules update, urges automakers to do so.
What is cylinder deactivation?
This technology has one of the more easy-to-understand names in automotive vernacular — unlike, say, a variable-geometry turbocharger.
Basically, the vehicle’s computer, ECU, determines when and how to turn off certain cylinders by closing the intake and exhaust valve, no air in or out, as well as stops injecting fuel into the cylinder.
The piston still moves up and down turning the crankshaft, it has to, and while pistons do experience pumping losses during to having to overcome air resistance when they pull in and expel air, there are no pumping losses when the cylinder is deactivated. The ECU is programmed to balance out the remaining pumping losses from the cylinders, which are still operating.
Basically, this means, even with different cylinders not working, the engine is more efficient by using less fuel and having a reduction in pumping losses.
Does it work?
Like most new engine technology, there are naturally questions on how much more efficient are we talking about and whether the trade offs (more sophisticated engine technology vs a traditional internal combustion engine) are worth it.
This is nearly an impossible question to answer since it really does depend on your driving style and how you use your truck.
Also, as of the time of this article, the 2021 Ford F-150 estimated fuel economy ratings are not out yet.
Also, while GM had a simple light showing V-4 or V-8 mode for years, the new GM trucks with Dynamic Fuel Management technology have 17 different cylinder patterns for turning off cylinders, which uses the engine’s 16 hydraulic valves to open and close cylinders by restricting oil pressure to them when needed. With the multitude of different cylinder combinations changing so rapidly, the system checks for changes 80 times every second, and there is no way to determine which mode or how many cylinders are actually working as a simple icon on the gauge cluster.
Also, and even more interesting, the new 2019 Chevy Silverado and GMC Sierra models actually returned worse EPA fuel economy than the 2018 model with the older active fuel management system, however, this was really about the additional weight of certain trucks due to adding more features and safety technology in those trims.
The bottom line on the F-150 V-8
New engine technology is always going to make truck fans suspicious since trucks are still seen as a tool and adding more complexity to a tool is often met with skepticism. The adage of “why fix it if it isn’t broke” is a pretty common phrase for truck buyers. However, the growing customer base of truck buyers and their desire to have improved fuel economy as well as CAFE regulations pushing for better miles per gallon, is going to lead to changes.
Fortunately, this isn’t a brand-new technology. Rather, it is really just Ford’s V-8 joining its rivals in offering, what is becoming, a rather basic engine technology.