quote:

Originally posted by PGT:
I drove the Mercedes GLE53 AMG which is a turbo-charged inline six with close coupled 48V mild hybrid last year as well as two Audi's (Q7 and SQ7). They really do strike a balance between fuel economy and performance that's terrific. The close-coupled electric gives instant torque and offsets a higher RPM spool turbo for maximum top-end power and fuel efficiency.

Wondering, how much more fuel efficiency are these new models providing? Typically the similar cars of 10 years ago were like 20 to 25 MPG, depending on driving habits. How are these new designs comparing?

It's probably only 2-4mpg honestly. That's why it's not really fair to call them hybrids in that sense. These designs are more about overcoming the limitations of 12V systems with an alternator and associate parasitic drag with modern requirements of safety systems and infotainment, lighting, etc as well as the aforementioned design benefits of instant torque of an electric motor to offset top-end power of a turbo. That's the rub with turbos....get them to spool for max torque at low RPM and they are out of their efficiency range on the top end which is why variable vane designs or twin scroll or even sequential turbos were employed. Using the 48V system simplifies this for the engineers.

quote:

Originally posted by radioman:
Wondering, how much more fuel efficiency are these new models providing? Typically the similar cars of 10 years ago were like 20 to 25 MPG, depending on driving habits. How are these new designs comparing?

My brother had a 1980 Datsun 200SX that got mid-twenties MPG. My new X3 is spec'ed for 26MPG. So really no better in gas mileage. But it does have 382HP and goes 0-60 in 4.4 seconds.

The mild-hybrid is said to add ~10-15% efficiency.