Tips for driving big automatic in snow?

[sk546]

Originally Posted by Discoman

How does the T8 cope with the fact that both axles are not connected like on the Haldex versions? I guess if your battery dies then you are running a purely FWD car.

With Constant AWD, Offroad or Power/Polestar Engineered Driver modes selected and the ICE running, the ISG (integrated Starter Generator) can provide sufficient power to the hybrid system to ensure the Electronic Rear Axle Drive (ERAD) is driven in conjunction with the FWD ICE even when the battery is showing zero range.
The T8 uses the ECU's (ICE and ERAD), traction control, ABS and other safety systems to detect what the front axles and rear axles are doing so its kind of like an E-Haldex rather than a mechanical unit. Other than there being no direct mechanical connection between the front and rear axles, the system seems to operate pretty seamlessly and if you are running in only electric drive (RWD) and the car detects loss of traction of the rear wheels i.e. wheelspin, the ICE is fired up to provide additional traction from the front axle.

[S90]

Originally Posted by sk546

With Constant AWD, Offroad or Power/Polestar Engineered Driver modes selected and the ICE running, the ISG (integrated Starter Generator) can provide sufficient power to the hybrid system to ensure the Electronic Rear Axle Drive (ERAD) is driven in conjunction with the FWD ICE even when the battery is showing zero range.
The T8 uses the ECU's (ICE and ERAD), traction control, ABS and other safety systems to detect what the front axles and rear axles are doing so its kind of like an E-Haldex rather than a mechanical unit. Other than there being no direct mechanical connection between the front and rear axles, the system seems to operate pretty seamlessly and if you are running in only electric drive (RWD) and the car detects loss of traction of the rear wheels i.e. wheelspin, the ICE is fired up to provide additional traction from the front axle.

I drove mine in power mode all day today, muhahahahaaa. The traction is epic. In AWD mode it's like its on rails. Say what you want about Volvo, but the drivetrain in the new ER models is amazing.

[ThomasC91]

My s90 on 20 inch summer tyres coped well the other day.

I nearly went into a field as I turned the bend doing 25mph, but she gained control lol.

It was a country road so no other cars about. I could have gone on the main road, but what's the fun in that.

[Discoman]

Originally Posted by sk546

With Constant AWD, Offroad or Power/Polestar Engineered Driver modes selected and the ICE running, the ISG (integrated Starter Generator) can provide sufficient power to the hybrid system to ensure the Electronic Rear Axle Drive (ERAD) is driven in conjunction with the FWD ICE even when the battery is showing zero range.
The T8 uses the ECU's (ICE and ERAD), traction control, ABS and other safety systems to detect what the front axles and rear axles are doing so its kind of like an E-Haldex rather than a mechanical unit. Other than there being no direct mechanical connection between the front and rear axles, the system seems to operate pretty seamlessly and if you are running in only electric drive (RWD) and the car detects loss of traction of the rear wheels i.e. wheelspin, the ICE is fired up to provide additional traction from the front axle.

Interesting, thanks. I've not driven a car with such a system. I've never been happy with any Haldex system and have a suspicion that the new torsen Audi quattro which runs in 2WD most of the time is not as good as the old S4s or indeed Imprezas I used to drive 20-30 years ago.

[PaulBendall]

Originally Posted by sk546

With Constant AWD, Offroad or Power/Polestar Engineered Driver modes selected and the ICE running, the ISG (integrated Starter Generator) can provide sufficient power to the hybrid system to ensure the Electronic Rear Axle Drive (ERAD) is driven in conjunction with the FWD ICE even when the battery is showing zero range.
The T8 uses the ECU's (ICE and ERAD), traction control, ABS and other safety systems to detect what the front axles and rear axles are doing so its kind of like an E-Haldex rather than a mechanical unit. Other than there being no direct mechanical connection between the front and rear axles, the system seems to operate pretty seamlessly and if you are running in only electric drive (RWD) and the car detects loss of traction of the rear wheels i.e. wheelspin, the ICE is fired up to provide additional traction from the front axle.

Fascinating and thanks for sharing. How did you discover this information?

I tried Off-Road tonight in the supermarket car park which is on the level; the car height raised and the drive profile changed. It seemed that the accelerator needed to be pressed more to increase speed than would be normal (finer control?). Increasing the speed above 20Mph resulted in the driver profile automatically switching to Constant AWD.

I engaged Off-Road again on a road with a decent descent, initially, the descent control and low-speed control didn't kick in, that is until I came off the accelerator and used the brakes. Then the instrument panel light up for hill descent control. In normal conditions, it felt a bit sluggish but I guess in slippery conditions you want slow adjustments to speed to ensure maximum grip. Probably need more practice before I'd want to use in anger.

Paul

[sk546]

Originally Posted by PaulBendall

Fascinating and thanks for sharing. How did you discover this information?

I'm an engineer by trade and so I make it my goal to fully understand (or as close to fully as I can get) the cars I own and how they operate.

It's a complex 4wd system that Volvo had decided to use for sure but the improvement I've seen from my first T8 to my current one shows Volvo are always improving their systems.

And yes, Offroad mode deactivates at speeds over 20mph. Obviously that's as fast as Volvo thinks you can go offroad for some reason, who know why they picked 20mph but that's your lot.
There must be a reason behind it (maybe diff or other traction settings are only usable below 20mph) and maybe someone on here knows why?