Volvo Hybrid Models Explained: Mild Hybrid vs Plug-In Hybrid
Mild Hybrid VS Plug-In Hybrid – Technical Specs
The principal difference between a mild hybrid system and a plug-in hybrid system is the size of the battery, with all other differences stemming from this. A mild hybrid system is similar to a conventional system, but with a smaller battery to reduce cost and weight. The system gives vehicles a low-end torque bump and eliminates the need for a starter motor. Fuel economy is improved somewhat, but you won’t see the kinds of numbers that you would get from a conventional hybrid drivetrain. Volvo’s B4, B5, and B6 drivetrains all come equipped with a mild hybrid system.
Volvo has only one plug-in hybrid (PHEV) drivetrain, the T8, but it is an exceptionally good drivetrain. The much larger battery pack in the T8 is mounted low, inside the transmission tunnel, for the best weight distribution and the lowest center of gravity. The battery is also much higher voltage, which it needs to be because PHEV vehicles are capable of traveling on electric power alone. You can also use electric power and gasoline power simultaneously for an enormous amount of combined power and incredible acceleration. Since the T8 has enough electrification to operate without gasoline at all, this is obviously the option that gives you the best fuel economy. The tradeoff is that it has to be plugged in to recharge if you want to really take advantage of the PHEV nature of the T8. It will run on gasoline when the battery is depleted, but so will a mild hybrid, and those are priced lower. That said, at-home charging stations aren’t particularly costly or difficult to have installed. And while pure electric vehicles need many hours to recharge, the smaller battery in the T8 does it in a fraction of the time.
Mild Hybrid VS Plug-In Hybrid – Models And Availability
| Drivetrain | Horsepower / Torque | Models |
|---|---|---|
| B4 | 194 HP / 221 LB-FT TQ | XC40 |
| B5 | 247 HP / 258 LB-FT TQ | XC40, XC60, XC90 |
| B6 | 295 HP / 310 LB-FT TQ | XC90 |
| T8 | 455 HP / 523 LB-FT TQ | XC60, XC90 |
Of Volvo’s gasoline drivetrains, the T8 is clearly the most powerful. It’s enough that the PHEV version of the XC90 can go from 0-60 in 5 seconds flat, and the XC60 Plug-In Hybrid managed it in just 4.5 seconds. The B4 provides the best fuel economy of any mild hybrid drivetrain, 27 MPG combined, in part because it only comes in the smallest model, but also because it’s the only FWD drivetrain; the rest are all-wheel drive. That said, the B5 isn’t far behind, 26 MPG in the XC40 and XC60, and 24 MPG in the XC90. Opting for the more powerful B6 in the XC90 returns 23 MPG. T8-equipped XC90s get 58 MPGe and can travel up to 32 miles on pure electric power. The XC60 T8 bumps those numbers up to 63 MPGe and 35 miles. Both mild hybrid PHEV drivetrains have their advantages, and most of the time, it will be lifestyle rather than drivetrain that determines which Volvo model is right for you. But you do still have options, and it’s always better to be able to make an informed decision.