- SUVs are getting larger while their V8 and V6 engines have been replaced by smaller motors.
- Smaller turbocharged engines benefit from improved fuel economy and better mid-range torque.
- But turbocharged engines can feel less refined and may be less reliable in the long run.
Over the past year, I’ve driven more than two dozen SUVs and something became immediately apparent: their engines are much smaller than they used to be.
Ford kicked off the current wave of engine downsizing a decade ago when its “EcoBoost” V6 engines began replacing V8s in its popular F-Series pickups and Expedition SUVs. The trend has since swept across the automotive industry thanks to the proliferation of hybrid technology, more advanced turbocharged powertrains, and increasingly strict fuel economy regulations.
As the engines have gotten smaller, vehicles have only gotten bigger and heavier. Behemoths of the early 2000s, like the Hummer H1 and Ford Excursion, were outliers during their time, towering over surrounding traffic, yet SUVs of their size are commonplace these days.
“I think it’s kind of the inevitable reality of being a carmaker right now,” Edmunds consumer insights analyst Joseph Yoon told Business Insider.
How and why engines are downsized
Engine downsizing can take different forms depending on the type of vehicle.
Generally speaking, it involves replacing a larger naturally aspirated engine with a smaller powerplant that relies on forced induction or the use of compressors, such as exhaust-driven turbochargers or belt-driven superchargers, to intake air and produce extra power.
For example, the new Infiniti QX80 and Lexus LX600 full-size SUVs both have twin-turbo V6 engines instead of their previous versions’ V8. While midsize SUVs like the Chevrolet Traverse, Infiniti QX60, and Toyota Highlander all recently dropped their V6s in favor of turbo four-cylinders.
I’ve even encountered some compact SUVs, like the Nissan Rogue, that have downsized their four-cylinder motors to turbocharged three-cylinder engines.
However, the results of engine downsizing can be hit or miss for consumers.
It’s not all bad news
For carmakers, transitioning to smaller, turbocharged engines comes with a host of benefits, chief among which is burning less fuel often while making more power.
The new V6-powered QX80 gained 50 horsepower and 13% better EPA fuel economy, while the LX600 has 26 more horsepower and a whopping 36% improvement in fuel economy compared to the outgoing V8 LX570.
At the same time, the four-cylinder Traverse gained 18 horsepower and a 9.5% bump in fuel economy.
Even more important than outright power is that turbocharged engines tend to have more bountiful mid-range torque than naturally aspirated engines, which translates to a feeling of more effortless acceleration for drivers, Gabe Shenhar, associate director of the auto test program at Consumer Reports, told Business Insider
Finally, downsizing to more efficient engines helps carmakers meet tighter emissions and economy regulations, allowing them to give EV-phobic consumers more ICE options in the marketplace.
“I think for a lot of people, there’s a lot of general anxiety about trying something new, especially if you’re not in a big urban metro area where it’s hard for you to find charging infrastructure,” Shenhar explained to Business Insider.
But there are downsides to downsizing
Despite their advantages, modern turbocharged engines have drawbacks for consumers, including inconsistent power delivery and a “general lack of refinement,” Shenhar and Yoon told Business Insider.
“Sometimes, with turbo engines, you have uneven throttle response. You get a little bit of a dead zone initially, then kind of an abrupt belated response,” Shenhar said.
That means it may take some getting used to your new powertrain, with a potential learning curve to accelerate smoothly.
For example, the new turbocharged four in a 2025 Infiniti QX60 I recently drove not only sounds cheap and tinny but also delivers its powered unpredictable surges.
And those theoretical gains in fuel economy from turbocharging may not materialize in everyday driving.
For example, the turbocharged, three-cylinder Nissan Rogue should have a three MPG advantage over the naturally aspirated four-cylinder it replaced. Instead, the three and four-cylinder Rogues returned identical fuel economy figures in Consumer Reports testing.
That has to do with the way turbocharged engines make their power and the way you apply the throttle.
Turbocharged engines are exceptionally efficient when cruising at a steady speed. However, the more you gun the throttle and the more boost you send into the engine, the less efficient it will be.
So, every time the driver aggressively stomps on the gas when driving, the more they “counteract the gains in fuel economy.” Shenhar explained.
Long-term reliability may be a concern
Turbocharged motors make power by compressing and violently forcing air into the combustion chamber to create a more powerful explosion. As a result, their components are more stressed and may not be as reliable in the long run as their naturally aspirated counterparts.
Turbochargers have traditionally been used on sports cars and models targeted at automotive enthusiasts. This is the first generation of vehicles in which they are widely deployed on family haulers that need to consistently and reliably get from point A to point B.
“I think we’re kind of in semi-uncharted territory in terms of what turbocharging is going to do because I think all auto enthusiasts know you can’t add power without taking things away whether that’s refinement, or whether that’s reliability, something has to give.” Yoon, the Edmunds automotive analyst, said.
However, both Shenhar and Yoon say there isn’t enough data to make a firm conclusion at the moment.
Shenhar notes that, based on Consumer Reports data, long-term reliability will depend more on the individual automaker than anything else.
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