Continental SportContact 7

[Rabbers]

My opinion of the Conti SC7s after twice driving the length of Germany in recent weeks remains high, their performance under frequent hard braking having been more than satisfactory.

As usual at the start of long autobahn drives I set the ACC at 180kmh, not in the realistic expectation of frequently reaching and maintaining this speed for long stretches given the density of the traffic and the numerous 80~120kmh limits, but so as to quickly regain speed after being overtaken by cars travelling at 200>kmh.

In situations of strong or very strong deceleration caused by slow or slowing vehicles ahead, I found myself initially obeying what remains, despite my long familiarity with the ACC, an instinctive - and personally rather embarrassing - impulse to "help" the deceleration by using the brake pedal, thus disengaging the system and retaking human control.  Why I feel a need to do this is not easy to analyse but, clearly, an objectively unjustified mistrust of the car's stopping capability in situations with potentially catastrophic outcomes has something to do with it.  However, my confidence in the ACC's ability to do its job without my feeling the need to interfere always returns as the autobahn drives proceed and I become re-accustomed to high speeds.  

On these recent drives my confidence undoubtedly returned more quickly than it usually does, and although I have no means of quantifying if and to what extent this might have been attributable to the feeling of effectiveness and stability transmitted by my tyres during hard braking, I was nevertheless certainly pleased by it.

[Linas.P]

Tyres were never an issue for me on autobahn, although I always had premium tyres so that isn't surprising. But the brakes would fade rapidly after few 200>130 stops. I even had one set of disks warped because of that.

As for braking yourself drinving on ACC - I think your instincts are right. I have tried the older version of ACC on autobahn (non-all speed one before LSS+, although I am not sure if RC ever got "all-speed" ACC, so it may be fundamentally the same) and whereas it was able to slow down from ~240 to ~160 in my case, it would do it very inconsistently e.g. it would start slowing down way too slow for the situation at first, then would slam on the brakes and activate seat belt pretensioners with associated impending doom beeps, slow down too much and then let off to finish... all that would upset the car and obviously occupants. I doubt ACC was developed in mind with suddenly deaccelerating by 100km/h as part of normal driving. I am sure use case for it is doing 130 and then slowing down to 110 when somebody pulls into outside lane to overtake, or just matching speed ahead of you in the slow lane, or I guess fast lane for that matter. What I am saying system is perfectly capable of matching the speed in 5, 10, 20... maybe 30km/h increments, but if you have to shave 100km/h off then I would be doing the same (by braking myself) and I think that is right thing to do. 

They probably need to make special version of ACC for Germany with different "adjustment".

[Rabbers]

On 7/3/2023 at 11:50 AM, Linas.P said:

..... They probably need to make special version of ACC for Germany with different "adjustment".

Not a bad idea, and likely to appeal to German Lexus owners whose appreciation of the autobahn network is not primarily based on the enjoyment of sphincter-tightening rates of deceleration as the natural consequence of driving flat out.

Observing the behaviour of big BMWs and Audis (in particular) on the autobahn I have sometimes thought that their cruise systems must be calibrated to allow much closer pre-overtaking distances than those of most other comparable cars.  Where a one-bar ACC setting won't bring my RC closer to a preceding vehicle than an estimated 60-40m depending on relative speeds, the aforementioned German marques often give the impression when approaching fast that they are going to collide with the preceding vehicle before braking violently and easing to something like a 20m distance.  To me this looks alarming but, obviously, alongside the drivers' apparently unexercised choice of "softer" settings, their systems are perfectly able - and are officially homologated - to handle such tight speed/distance ratios.  What, unfortunately, the systems cannot do is to monitor the state of the brakes and tyres.

 

 

[Rabbers]

When changing to winter tyres this morning I took a close look at the treads on my SC7s after 14000km (evenly divided, I would estimate, between motorway, other roads, and town/city).  All four were ~6mm, the rears maybe a tad less.  So I would say that satisfactory resistance to wear can be added to the tyres’ merits.