40tdi - mild hybrid actually do anything?

[kennyboy993]

Does anyone know what the mild hybrid system actually does in the 40TDI? I've read more than 1 article and can't see anything that specifically talks about anything other than features available in any modern diesel i.e.

stop/start
coasting at speed - that's just the engine being turned off at speed?
regen braking - though when does that energy get used?

I expected to see something like 'torque fill at low revs' etc. I can't detect any mild hybrid system being evident at all - am I missing something?

 

[elan2s]

The primary purpose of the mild hybrid feature on the 40/45 TDi and TSi is to power the essential systems in the car, such as brakes and power steering when the engine shuts down when the vehicle is moving, you get the green "A" in a circle in the same way as you get it when the engine goes into stop/start mode when stationary. In the facelift C7 and on other Audis there were many criticisms of the stop/start system switching off when the car was still moving and the driver losing power steering and brake servo assistance. The 50 and 55 engined cars have a 48v system since these cars can be specced with things options which operate at the higher voltage. The "region braking" is just the process by which the hybrid battery is recharged (thus using energy which would otherwise go to waste).

 

[kennyboy993]

Makes sense, cheers - I kinda get the regen bit, I had a plug-in hybrid before the audi

Though these cars do have an electric motor in the drivetrain somewhere right? when are these being deployed on the 40tdi?

 

[MCarda]

Makes sense, cheers - I kinda get the regen bit, I had a plug-in hybrid before the audi

Though these cars do have an electric motor in the drivetrain somewhere right? when are these being deployed on the 40tdi?

unfortunately no electric motor on the drivetrain unless the car is a TFSIe model. No idea on if there are plans to deploy this on diesels as of yet.

 

[kennyboy993]

cheers - have learnt something here, just done a bit more reading based on your post too.

I thought all MHEV systems included power assist, turns out some of them don't - Audi 12V being one of them

 

[Frizzley]

cheers - have learnt something here, just done a bit more reading based on your post too.

I thought all MHEV systems included power assist, turns out some of them don't - Audi 12V being one of them

If your interested the this article provides a bit more detail on how the 12v and 48v systems work. I’ve got the 48v on my S5 and tbh the car only seems to coast on the odd occasion

Audi’s mild-hybrid systems: 12V for 4-cylinders, 48V for 6- and 8-cylinders

Audi will begin introducing new mild-hybrid drive vehicles (MHEVs) this year. The next generation of luxury sedans, the Audi A8, will have 48V MHEV systems regardless of engine type. Audi offers the MHEV drives in two variants. For the four-cylinder engines they are based on the familiar 12-volt...

www.greencarcongress.com

 

[elan2s]

This animation from Audi may help as well https://www.audi-mediacenter.com/en/audimediatv/video/audi-a4-sedan-tfsi-12-volt-mhev-animation-4632

There is also one for the 48v system, which seems to use the starter alternator as a means of slowing the vehicle rather than relying on brakes. Something not mentioned int he 12v video so may be a difference between the two systems.

 

[kennyboy993]

good stuff, thanks guys