ACC

[sportse]

It's very strange - some people get on great with the systems, but others have real problems.

Perhaps there are different software/sensor versions that have different performance?

I took my car back to the garage shortly after purchasing to have them check the systems and they said they were running fine with no errors. Perhaps the differences don't show up on a normal test when plugged in.

[Kremmen]

I'm very suspicious that mine is nowhere near the quoted 1.2 secs distance on 1 bar @ 65mph.

I was going to time it this weekend but having used the LIM facility with good results I'm just going to ditch ACC.

ACC is probably perfectly OK on quiet roads to maintain a speed or on a road where you just want to auto follow,  but on a carriageway with frequent lane changes to overtake it's hopeless IMO.

[Neil Ives]

I'm very suspicious that mine is nowhere near the quoted 1.2 secs distance on 1 bar @ 65mph.

I was going to time it this weekend but having used the LIM facility with good results I'm just going to ditch ACC.

ACC is probably perfectly OK on quiet roads to maintain a speed or on a road where you just want to auto follow,  but on a carriageway with frequent lane changes to overtake it's hopeless IMO.

I'm afraid that you might have trouble even on a quiet road. I've had my ACC react to a vehicle parked in a layby. I was half expecting the reaction so was ready to put my foot on the gas pedal.

[Kremmen]

I've not had any issues if I'm square in lane. It's when changing lanes I've had some unexpected results. The last thing I want on a motorway is giving other drivers unexpected brake lights. Makes me look like I need P plates.

[sportse]

I tried timing one bar ACC last week by counting - it did seem to be about 1.2 seconds on a clear road with just one car in front.

The problem is, when there is traffic about it increases the gap randomly and doesn't keep to the 1.2 seconds. If I'm using it, I have to soft override it with accelerator to keep the gap.

[nowster]

I'm very suspicious that mine is nowhere near the quoted 1.2 secs distance on 1 bar @ 65mph.

I have it set to 4 bars. "Only a fool breaks the two second rule."

[Kremmen]

I fully agree but go back to my post #55 in this thread.

Just look at that gap 1 bar was holding me back at 51mph, it's massive.

[R2D3]

Newbie question. Can you set cruise control to just be a normal cruise control rather than ACC?

[nowster]

I fully agree but go back to my post #55 in this thread.

Just look at that gap 1 bar was holding me back at 51mph, it's massive.

Firstly, dashcams have very wide angle lenses and hence exaggerate distances.

Secondly, have you timed it using a landmark or a shadow? (eg. One elephant, two elephant.)

[sportse]

Newbie question. Can you set cruise control to just be a normal cruise control rather than ACC?

Unfortunately not.

In many cars you can (my last one did it, but the radar based ACC was so good I never needed to) - press cruise control button once for ACC & if you held it down for a couple of seconds it switched to normal CC operation instead.

[Kremmen]

I fully agree but go back to my post #55 in this thread.

Just look at that gap 1 bar was holding me back at 51mph, it's massive.

Firstly, dashcams have very wide angle lenses and hence exaggerate distances.

Secondly, have you timed it using a landmark or a shadow? (eg. One elephant, two elephant.)

I was going to do that but I've found that LIM does exactly what I want so I've taken ACC off the agenda.

What I've subsequently found is that when I'm on the M4 motorway, which changes from 50 to 60 westbound and 60 to 50 eastbound at J 8/9. By pressing the LIM button again from LIM it switches to Intelligent LIM and when it spots the 50 or 60 signs it automatically switches the limit up or down, perfect.

[ColinB]

By pressing the LIM button again from LIM it switches to Intelligent LIM and when it spots the 50 or 60 signs it automatically switches the limit up or down, perfect.

Be careful about that. On the MK3 (and I've not seen anything suggesting it's better on the MK4) the sign recognition just isn't good enough, it's liable to see the wrong sign. Also the system doesn't anticipate the changed limit sign as you would manually when you see it ahead, so you actually pass the sign at the wrong speed which could land you with a ticket.

[nowster]

By pressing the LIM button again from LIM it switches to Intelligent LIM and when it spots the 50 or 60 signs it automatically switches the limit up or down, perfect.

Be careful about that. On the MK3 (and I've not seen anything suggesting it's better on the MK4) the sign recognition just isn't good enough, it's liable to see the wrong sign. Also the system doesn't anticipate the changed limit sign as you would manually when you see it ahead, so you actually pass the sign at the wrong speed which could land you with a ticket.

So true! If you're going through roadworks it may pick up a 15 mph sign for the works traffic and apply the brakes unexpectedly. Beware!

[Neil Ives]

I have found the sign recognition system rather poor, at least, on the roads around here that have greenery growing over the signs. Motorway signage may well be OK.

[Kremmen]

I've been down the M4, which is the only place I'm intending using the I-LIM and before using LIM I've been keeping my eye on the dash display.

So far it's been spot on.

I did post an image further up (post #55 again) showing that 40 50, the dash showed it had correctly picked up the 50.

There are also a few places where there are 10mph signs for the vehicles in the coned off single lane roadworks sections and its ignored those as well.

However, I hear what you're saying and I think I'll just use it to auto change at J 8/9 then switch back to LIM and keep an eye on the dash for any blips.