XDL - Effective or Not?

[redline3345]

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.

[K1W1]

Are you 100% sure that XDL is actually fitted to your car?
A bit of paper signed by the dealer several months before manufacture doesn't actually guarantee that robot at the factory was told to fit XDL.

[dArK5HaD0w]

if u have access to the vcds tool, and ur car is fitted with "xds" (i believe its the same as 'xdl'), then u'll b able to modify the xds settings between 'weak', 'centre' (default) & 'strong'.

have a read here for more info. it applies to a mk6 golf gti, but it should b same'ish.

maybe u need to change ur setting to 'strong'.

[Gti Dave]

I wonder how much I have missed by having a pre-facelift without XDL?

[redline3345]

if u have access to the vcds tool, and ur car is fitted with "xds" (i believe its the same as 'xdl'), then u'll b able to modify the xds settings between 'weak', 'centre' (default) & 'strong'.

have a read here for more info. it applies to a mk6 golf gti, but it should b same'ish.

maybe u need to change ur setting to 'strong'.

Thanks dArK5HaDOw - have yet to get a hold of vcds - that is next on my list of purchases for the car - at least that may confirm if the car actually has XDL, as well as give me the ability to change the setting as you suggest.

Are you 100% sure that XDL is actually fitted to your car?
A bit of paper signed by the dealer several months before manufacture doesn't actually guarantee that robot at the factory was told to fit XDL.

Kiwi - that's what I was asking in the last sentence - how do you confirm if the car actually is fitted with XDL? - particularly as all the physical attributes on my car seem to indicate it does not have it. I don't have a lot of trust of salespeople as a result of bad experiences, that's why I asked for it (and other add ons that they assured me were included) in writing.

I recall there was a also fair bit of chat on this forum just prior to July 2010 about the MY11 models having XDL. I distinctly remember that there was comment made a couple of times that all MY11 models - and specifically it was stated that meant cars made from July '10 onwards - would have XDL.

Why, if it was officially intended as an option on Aus MY11 cars, would the factory not have included it?

[K1W1]

Kiwi - that's what I was asking in the last sentence - how do you confirm if the car actually is fitted with XDL? - particularly as all the physical attributes on my car seem to indicate it does not have it. I don't have a lot of trust of salespeople as a result of bad experiences, that's why I asked for it (and other add ons that they assured me were included) in writing.

Isn't there a plate somewhere on the car (boot?) that lists every option fitted? If not the information will be listed in Skodas service system.
The first reason I suggested querying whether the XDL is fitted is simply because your car does not seem to be acting the way you would expect if it was so by going to the source and making 100% sure it's there first you can then take steps to get it working correctly. When I problem solve I always start at the beginning and if it's not there this whole discussion is irrelevant because you have to have a different discussion with your dealer.
The second reason for my suggestion is simply that what is fitted and what is not fitted to Skodas does seem to be a little variable at times.

[spellbound]

I wonder how much I have missed by having a pre-facelift without XDL?

Stepping out of my pre FL with apr stage 1 into the gti was certainly a step up with XDL , corners attacked much harder and no torque steer to speak of .

How ever i have noticed since fitting stage 1 to the GTI that it can get bad habits if the power is applied brutally in tight corners , not as loose as the RS .

There are limits to XDL with so much power being applied .

[dArK5HaD0w]

Isn't there a plate somewhere on the car (boot?) that lists every option fitted? If not the information will be listed in Skodas service system.

the xdl was not an 'option', atleast from my11 onwards.

the build sticker in the boot does not list every single thing that's been fitted into the vehicle. for example mine is fitted with a rear-wiper, yet there is no 'code' for it on my build sticker. this was made standard from my11 on. on my10 models, it was a $150 extra. i ordered mine in jun 10, using a my10 octavia rs brochure. on that it clearly showed "rear window wiper (liftback only)" as an option. i forgot to tick this when i ordered mine. but thankfully, i came to know my11 has it as standard, and i was getting an my11 model.

with regards to ESP, the only thing it mentions (on my build sticker) is "1AT = Electronic Stabilization Program (ESP)".
i don't believe it will list seperate codes for 'ABS', 'EBD', etc etc.

MY10 - "ESP - Electronic Stabilization Program (incl. ABS, EBD and ASR)
MY11 - "ESP - Electronic Stabilization Program (incl. ABS, EBD, ASR, XDL and hill hold control)

to be sure to be sure, someone with an my10 build should have a look at the build sticker and see if "1AT" is listed, or something else in its place.

[redline3345]

Isn't there a plate somewhere on the car (boot?) that lists every option fitted? If not the information will be listed in Skodas service system.
The first reason I suggested querying whether the XDL is fitted is simply because your car does not seem to be acting the way you would expect if it was so by going to the source and making 100% sure it's there first you can then take steps to get it working correctly. When I problem solve I always start at the beginning and if it's not there this whole discussion is irrelevant because you have to have a different discussion with your dealer.
The second reason for my suggestion is simply that what is fitted and what is not fitted to Skodas does seem to be a little variable at times.

Kiwi
Thanks for the suggestion, makes sense to ensure it's there in the first place. Mine has the codes: 1AT = Electronic stabilization program (ESP) and 2UC = Sports version, both of which do not distill out if XDL is included.

This is getting more mysterious...

Spellbound
There are limits to XDL with so much power being applied . We weren't limited at Calder with the GTI MKVI's and the XDL seemed to cope with not only us competition winner tyre kickers, but also v8 supercar drivers giving their all on the corner prior to taking us on hot laps......maybe it was tweaked for demo/product launch purposes?!?

[spellbound]

Spellbound
There are limits to XDL with so much power being applied . We weren't limited at Calder with the GTI MKVI's and the XDL seemed to cope with not only us competition winner tyre kickers, but also v8 supercar drivers giving their all on the corner prior to taking us on hot laps......maybe it was tweaked for demo/product launch purposes?!?[/QUOTE]

I did the hot laps at the TRACK DAY , but none of those cars had APR upgrades , my car was very controlled until i got the stage 1 .

As you well know there is a lot of power and torque 400nm+ to cope with , sometimes i feel like the xdl has gone missing , but only in confined quarters , pretty sure it was std on the RS from 2011 .