In 2019, Volvo announced an updated powertrain fitted with a 48-volt mild hybrid system. The integrated starter-generator and regenerative brake-by-wire refilling a small battery could increase fuel economy by up to 15% in real-world driving. There are three layouts, dubbed B4, B5, and B6 that the Swedish automaker’s already been rolling out globally. Next year two of them, the B5 and B6, come to the U.S. for the first time under the 2022 Volvo S60, S90, V90 XC, and XC60. The EPA’s fuel economy site shows all of those models making small fuel economy gains, too.
The B4 and B5 powertrains contain both gas and diesel mild-hybrids, the B6 is gas-only. All of the gas options (Volvo doesn’t offer diesels here) will start with a 2.0-liter four-cylinder, the B5 adding a turbocharger, the B6 adding a turbocharger and a supercharger.
Per the EPA, the front-wheel drive 2021 Volvo S60 returns 23 miles per gallon in the city, 34 on the highway, and 27 combined. The new 2022 Volvo S60 B5 betters that with 26 city, 35 highway, and 30 combined. The 2022 S60 B5 AWD bests the 2021 model with the both versions of the non-hybrid 2.0-liter engine by one to three miles per gallon in nearly every category. The only model that does better, for obvious reasons, is the 2021 S60 AWD PHEV, which has been renamed S60 T8 AWD Recharge.
The 2022 Volvo XC60 comes in AWD B5 spec with the turbocharged 2.0-liter, and AWD B6 spec with the turbo- and supercharged 2.0-liter. Gains are smaller here, the EPA showing a one-mpg increase in the city when comparing the 2021 XC60 to the 2022 B5 model. With the B6 powertrain, the 2022 XC60 improves by one mpg in the city and combined compared to the 2021 model. The EPA site doesn’t show a front-drive XC60 for next year, and the XC60 AWD PHEV is already referred to as the XC60 T8 AWD Recharge.
It’s possible horsepower ratings will change slightly for the mild-hybrid rigs next year, but not enough to change the driving experience.