Manually engaging 4x4 mode possible?

unixnerd · 06-27-2022, 03:24 PM

Hi, I'm buying a 2006 2.0d for a friend in a few days. Despite owning BMWs for 30+ years it'll be my first time driving a diesel or 4x4 BMW. It only has 63k miles but I'll give it a full service and look over anyway. It's only been driven around town so no doubt full of carbon, I'll remove and clean the EGR valve.

I run a '99 RAV4 3 door in the winter. I live in a ski resort and only use it in snow. When it finally dies I've been toying with an X3 2.5i (because all 3.0i were automatics in UK!).

The RAV is full time 4x4 with a lockable centre diff and it's been useful quite a few times. Now I suspect xDrive has no centre diff but I'm wondering if there's a mod to manually enable four wheel drive mode?

richardodn · 06-27-2022, 08:06 PM

The BMW Xdrive systems are a full time AWD system with a electronically controlled center differential. In a nutshell, the electronics control the front/rear torque split with a default 60% rear bias. Up to 100% of the torque can be sent to either axle depending on conditions. (100% to the front axle only occurs if the rear is getting 0 traction.) Side to side torque split is governed by using the Dynamic Stability Control (DSC) system to apply the brakes to whichever side starts slipping.

So to answer your questions.
1. It does have a center diff
2. It can't be locked but that wouldn't make sense in this context since it's not mechanically controlled.
3. There's no mod to enable 4WD mode because it's a full time AWD system.

unixnerd · 06-28-2022, 04:45 AM

Thanks for that :-) I'd thought it was 100% RWD unless the system detected wheel slip.

06-27-2022, 03:24 PM	#1
unixnerd Second Lieutenant 213 Rep 211 Posts Drives: E46 325Ci, Z4, E30 318iS Join Date: Jul 2020 Location: Scotland iTrader: (0)	Manually engaging 4x4 mode possible? Hi, I'm buying a 2006 2.0d for a friend in a few days. Despite owning BMWs for 30+ years it'll be my first time driving a diesel or 4x4 BMW. It only has 63k miles but I'll give it a full service and look over anyway. It's only been driven around town so no doubt full of carbon, I'll remove and clean the EGR valve. I run a '99 RAV4 3 door in the winter. I live in a ski resort and only use it in snow. When it finally dies I've been toying with an X3 2.5i (because all 3.0i were automatics in UK!). The RAV is full time 4x4 with a lockable centre diff and it's been useful quite a few times. Now I suspect xDrive has no centre diff but I'm wondering if there's a mod to manually enable four wheel drive mode? __________________ www.unixnerd.co.uk - providing Nerdy BMW stuff since 1996!
	Appreciate 0 Tweet Quote

06-27-2022, 08:06 PM	#2
richardodn First Lieutenant 161 Rep 352 Posts Drives: '12 X3 35iX/'20 440ix cabrio Join Date: Dec 2018 Location: Denver, CO iTrader: (0)	The BMW Xdrive systems are a full time AWD system with a electronically controlled center differential. In a nutshell, the electronics control the front/rear torque split with a default 60% rear bias. Up to 100% of the torque can be sent to either axle depending on conditions. (100% to the front axle only occurs if the rear is getting 0 traction.) Side to side torque split is governed by using the Dynamic Stability Control (DSC) system to apply the brakes to whichever side starts slipping. So to answer your questions. 1. It does have a center diff 2. It can't be locked but that wouldn't make sense in this context since it's not mechanically controlled. 3. There's no mod to enable 4WD mode because it's a full time AWD system. __________________ 1986 Delphin 528e - Roof rack equipped lumber hauler. 2008 Platinum-Beige X3 3.0si - Current project 2012 Alpine White X3 xDrive35i - My new snowmobile. 2020 Estoril Blue 440i xDrive cabrio w/MPPSK - This car is a blast to drive.
	Appreciate 0 Quote

06-28-2022, 04:45 AM	#3
unixnerd Second Lieutenant 213 Rep 211 Posts Drives: E46 325Ci, Z4, E30 318iS Join Date: Jul 2020 Location: Scotland iTrader: (0)	Thanks for that :-) I'd thought it was 100% RWD unless the system detected wheel slip. __________________ www.unixnerd.co.uk - providing Nerdy BMW stuff since 1996!
	Appreciate 0 Quote