I've just test-driven an XF S 3.0 litre diesel (MY11, here in Australia), and I was wondering if anyone can tell me if the MY12 permits the use of cruise control AND automatic speed limiting (i.e. braking, as per the XJ).

I ask because whilst ASL functions, it appears that cruise control cannot. I could ask the local dealer, but I'm sure that the good folk here can tell me sooner...

And should I assume that Australian-spec vehicles might be different?

 

Hmmm. Very quiet forum... My check of all available sources tell me that speed limiting cannot occur at the same time as cruise control. Perhaps XF drivers aren't interested in either!

 

Yeah, from what I've seen, ASL is typically the last on the list of features that XF owners want.

 

Yeah, I don't know what it does or how to turn it on.
Anything called "speed limiter" isn't something I want.

 

Actually, I like the ASL. You are correct that you cannot use CC while in ASL mode. ASL is perfect for variable traffic conditions like in rush hour, when you don't want to exceed a certain speed but the variable conditions aren't suited to cruise control. Another problem I have with CC is potential calf fatigue. I like to keep my foot over the throttle, so that it can easily move to the brake if necessary, but find I either get tired of holding my foot slightly off the pedal, or if resting on the pedal tend to override the cruise which defeats the purpose. With ASL, however, it's really hard to override unless you "kickdown". I think it's a great feature. Adaptive cruise (ACC) may overcome the variable condition problem with CC, but reviewers say ACC has problems of it's own like aggressive braking when it thinks the car in the adjacent lane is in front of you when you are in a bend.

 

ASL is enabled with a switch near the parking brake. Then you use the thumb wheel on the steering wheel to set your desired limit speed (same wheel used to set cruise speed). The ASL can be canceled with the cancel button, overridden with kickdown (me like!) and resumed with the RESUME button. Of course it can be disabled with the switch, which makes CC available.

 

The main reason for ASL is the average speed limit zones common in British highway construction zones. It is pretty much useless over here except for situations where speeding tickets are an issue(as in you have too many, or you are following a cop over a long distance!).

Average speed limits are enforced by camera timers which recognize license plates and time elapsed between two fixed locations. Violation gets you a ticket in the mail with demerit points attached! Such tickets would violate constitutional rights in most places in Canada so can only result in a fine here. Only Alberta still uses camera tickets, literally a license to speed.

 

Ahhh, suddenly the ASL makes perfect sense (for a Brit car). Thanks!

I'll still never use it for anything....

 

Okay: can see why this is set up this way, even though a Renault that I hired in Europe back in 2000 could do both. I can see how it might be useful here in Australia, where there is no such thing as 'rights', and instead plenty of speed cameras, including average speed cameras.

 

How would having ASL enabled during cruise control be of any use? You set your cruise speed and the car stays at that speed. It's not like your cruise control will vary enough to the point where you'd need to set the ASL to limit the top speed. In what situation would you want to have both enabled?

 

Well, surprisingly yes actually. The cruise would be set to a lower speed than the ASL. then the driver could increase speed during a cruise event but not exceed a pre-set limit. In an average speed zone this could be useful if the driver can do some simple arithmetic in his head or there is a trip computer capable of updating actual average speed.

 

Virtually all the time here in Australia: there are many roads which are steep enough to cause overrun, and speed cameras are often placed at the bottom of hills.

Decent engine braking will go part way to preventing this, but nothing beats a vehicle with cruise AND overspeed control (some cars even brake as needed, but Al's not the XF).

 

Actually the ZF in the XF uses engine braking surprisingly well. The lock up clutch is locked up in 2-6 gear. With the throttle closed you have full engine braking as if a manual gearbox were fitted. You do have to downshift manually to increase engine braking but that is also true of any manual gearbox. It is the ZF that sold me on the car.

 

That's really good to know. I've driven both the 2.2 and 3.0 litre diesels, and thought that engine braking wasn't sufficient to avoid fines. Will have to test again.