Got a 2022 GLS450 in shop today for service
 

Wow, no serpentine belt. Ac and pwr strg are electric and no alternator. The electric motor/alternator is installed between the engine and transmission.

At 18k miles the right rear tire looked like a race slick already.

For the serpentine belt do you just put a ratchet on the tensioner, release tension, and easily replace the belt? Like on my Lexus? My 81 300SD is way harder to replace a belt.

What could have happened to the tire?

It doesn't have a serpentine belt, all accessories are electrically driven and the alternator is incorporated into the low-speed electric motor assist off the flywheel.

I always disliked V-belts, serpentine belts were a big improvement and no serpentine belts at all seem like an even bigger improvement.

The electrically driven HVAC thing worries me a little but the electrical power steering on my GLK has been flawless and it makes a whole bunch more sense to use electricity for power assist than pumps, hoses seals ect, in that application.

The 48V system was the last instructor-led training course I took before I retired. It's a really cool setup but really just a stop-gap measure. MB went as far as they could with a 12V/250A system. The first thing I noticed was how seamless the ECO Start/Stop system works. The engine cranking speed of the 48V motor is only slightly below idle speed so you'll hardly notice the frequent shutdown/startup when creeping along in bumper-to-bumper traffic...

A stop-gap measure before go all-electric?

Being able to apply force all around the flywheel with a defined ramp-up torque curve would really smooth out the transition from ICE to EV operation. I'd guess it could be almost totally seamless in contrast to the systems that rely on the convention starter motors where its just plain annoying.

A couple of years ago I actually down-graded from a 2020 GLC to an older car and one of the factors that led me down that road was the stupid auto start-stop 'feature' that had to me manually turned off every time I started the car.

I'm thinking this is where I'll be headed in the future when looking for something else. Last vehicle I added to the fleet was the 2012 GL450 - v8, no turbo/supercharger. I'm of the opinion that the engine in it is a longer lasting engine (before you have to go into timing chain components) than the m276/278.

If anyone has a pic/cutaway showing what is between the engine and transmission on the GLS450 vehicle I'd be interested in seeing it.

Just out of curiosity I got a price for the electric compressor from the dealer and it was right at $1000 which I did not think was that bad. Maybe this could be an upgrade option for the 123 cars. There is no reason it would have to be mounted to the engine. Tesla has been running the electric compressor for a few years now and as Tim said, we've had no issues at all with the electric power steering in the GLK350.

The rear tires were severely over inflated so that did not help in getting long life out of them. There is still a little tread left on the outer edges. She said she does not drive it hard but I suspect she likes the acceleration of the motor/turbo engine. Her hubby has a C63 that he drives on occasion.

Y'all excuse me while I go change the fuel filter on a 1980 240D that is in the shop:).