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I have trawled extensively, but cannot find a thread on XDL effectiveness.
I have a MY11 Octavia vRS wagon (ordered in July ‘10 as a MY11 and delivered December 2010), which was sold to me with an assurance (written) from the dealer that it has XDL (Extended Differential Lock), similar to MK VI GTI.
I was fortunate enough to win a competition in Nov 2009 when the MK VI GTI being launched at racetracks, and was invited to “test” the new GTI at Calder Raceway. One of the demonstrations was the new XDL; we drove MKV’s at speed around a long sweeping corner that was wet down, followed by the MKVI. The difference was significant enough to impress me; the MK V predictably understeering off the track, whereas the MK VI stayed fairly much on line albeit with some minor lurching while the XDL cut in and out. Effective enough to increase the primary safety of the vehicle though.
My experience with my Octy & XDL has not been as impressive. When accelerating in the wet, the inside front wheel spins quite readily, with the TC light flashing furiously, but the inside wheel still freely spinning – the XDL not seeming to be effective in bringing a halt to the lack of traction. It does this at all speeds; slow, moderate as well as fast.
The blurb in the Octavia brochure states of XDL: “The Electronic Differential Lock is an extension to the EDL (Electronic Differential Lock) function. When cornering, the XDL responds to the unloading of the front wheel on the inside of the corner. The ESP hydraulics are used by the XDL to apply pressure to the wheel on the inside of the corner to prevent wheel spin. This improves traction and reduces the tendency to understeer. As a result of the one-sided and precise braking pressure, cornering is sportier, quicker and more accurate”.
There appears the implication with the above wording (responds to unloading; prevent) that the XDL is designed to anticipate & prevent the wheel-spin – presumably using the yaw sensor(s) and steering input to work out the car is cornering moderately fast (or really fast as the case may be) and brake the inside front wheel accordingly.
More recently I had the opportunity to go for a run around Lakeside Park raceway with some of the VWW guys. I was in the market for new tyres anyway, so wasn’t that worried about wearing the tyres. I check the tyres regularly and prior to setting out to the track a checked showed the wear on all tyres remained quite even, with about 1mm of tread above the TWI’s and no sign of feathering or uneven wear.
Arriving home after some enthusiastic laps of Lakeside, I checked the tyres. Both front tyres were now completely worn bald, but only in the inside 1/3 of the front treads, the front right slightly more worn than the front left. Lakeside is a clockwise circuit, with more right turns than left.
On the track, there didn’t appear to be much in the way of wheel-spin in the corners, however with my concentration focussed in staying away from Armco and other cars, I must admit I wasn’t listening for it – I also did not notice the TC light, but again was focussed on the track and other cars. I was checking for dash lights, temp etc on the straight where it wasn’t so frantic.
I note on my car that on turning to lock, the inside wheel has positive camber, whereas the outside wheel has negative camber. Logically, if the XDL was working, the inside front should not be spinning, but I am curious as to why the inside of the tread has been worn on these tyres. If the inside wheel was spinning, then the outside of the tread should be worn with the inside wheel cambering positively in turns. The caveat on this might be that the track was significantly cambered in a few of the corners, and the resulting pitch of the car when cornering (+track camber) could result in the inside wheel actually be contacting the track on the inside of the tread (hard to see when driving though!) The other (remote?) possibility is that the XDL was working so well, that the inside wheel was being braked and it was the outside (negatively cambered) wheel that was spinning, although this is hard to believe as the car would have then understeered off the track if that was the case (and I don’t think XDL works that well) – and it was staying on line.
If it is that the track camber and car pitching caused contact on the inside of the tread of the inside front wheel, then it would appear that the XDL is not working effectively to prevent wheel-spin & resulting in scrubbing the tyres bald on the inside of the treads, which would concur with my experience on the road in the wet. This might prompt me to question if my car actually does have XDL. Is there any way to confirm & has anyone had any experience with XDL effectiveness?
Any input would be appreciated.
I have a MY11 Octavia vRS wagon (ordered in July ‘10 as a MY11 and delivered December 2010), which was sold to me with an assurance (written) from the dealer that it has XDL (Extended Differential Lock), similar to MK VI GTI.
I was fortunate enough to win a competition in Nov 2009 when the MK VI GTI being launched at racetracks, and was invited to “test” the new GTI at Calder Raceway. One of the demonstrations was the new XDL; we drove MKV’s at speed around a long sweeping corner that was wet down, followed by the MKVI. The difference was significant enough to impress me; the MK V predictably understeering off the track, whereas the MK VI stayed fairly much on line albeit with some minor lurching while the XDL cut in and out. Effective enough to increase the primary safety of the vehicle though.
My experience with my Octy & XDL has not been as impressive. When accelerating in the wet, the inside front wheel spins quite readily, with the TC light flashing furiously, but the inside wheel still freely spinning – the XDL not seeming to be effective in bringing a halt to the lack of traction. It does this at all speeds; slow, moderate as well as fast.
The blurb in the Octavia brochure states of XDL: “The Electronic Differential Lock is an extension to the EDL (Electronic Differential Lock) function. When cornering, the XDL responds to the unloading of the front wheel on the inside of the corner. The ESP hydraulics are used by the XDL to apply pressure to the wheel on the inside of the corner to prevent wheel spin. This improves traction and reduces the tendency to understeer. As a result of the one-sided and precise braking pressure, cornering is sportier, quicker and more accurate”.
There appears the implication with the above wording (responds to unloading; prevent) that the XDL is designed to anticipate & prevent the wheel-spin – presumably using the yaw sensor(s) and steering input to work out the car is cornering moderately fast (or really fast as the case may be) and brake the inside front wheel accordingly.
More recently I had the opportunity to go for a run around Lakeside Park raceway with some of the VWW guys. I was in the market for new tyres anyway, so wasn’t that worried about wearing the tyres. I check the tyres regularly and prior to setting out to the track a checked showed the wear on all tyres remained quite even, with about 1mm of tread above the TWI’s and no sign of feathering or uneven wear.
Arriving home after some enthusiastic laps of Lakeside, I checked the tyres. Both front tyres were now completely worn bald, but only in the inside 1/3 of the front treads, the front right slightly more worn than the front left. Lakeside is a clockwise circuit, with more right turns than left.
On the track, there didn’t appear to be much in the way of wheel-spin in the corners, however with my concentration focussed in staying away from Armco and other cars, I must admit I wasn’t listening for it – I also did not notice the TC light, but again was focussed on the track and other cars. I was checking for dash lights, temp etc on the straight where it wasn’t so frantic.
I note on my car that on turning to lock, the inside wheel has positive camber, whereas the outside wheel has negative camber. Logically, if the XDL was working, the inside front should not be spinning, but I am curious as to why the inside of the tread has been worn on these tyres. If the inside wheel was spinning, then the outside of the tread should be worn with the inside wheel cambering positively in turns. The caveat on this might be that the track was significantly cambered in a few of the corners, and the resulting pitch of the car when cornering (+track camber) could result in the inside wheel actually be contacting the track on the inside of the tread (hard to see when driving though!) The other (remote?) possibility is that the XDL was working so well, that the inside wheel was being braked and it was the outside (negatively cambered) wheel that was spinning, although this is hard to believe as the car would have then understeered off the track if that was the case (and I don’t think XDL works that well) – and it was staying on line.
If it is that the track camber and car pitching caused contact on the inside of the tread of the inside front wheel, then it would appear that the XDL is not working effectively to prevent wheel-spin & resulting in scrubbing the tyres bald on the inside of the treads, which would concur with my experience on the road in the wet. This might prompt me to question if my car actually does have XDL. Is there any way to confirm & has anyone had any experience with XDL effectiveness?
Any input would be appreciated.
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