the_duke

So I took my car in to have it aligned and ACC calibrated after installing my new upper control arms. The ACC was not working when I bought the car. I have been able to make it work a couple of time by resetting, un-coding and re-coding it. However it would only work for a short while and then stop working. It never worked correctly as it tended to see cars in the wrong lane etc. Unfortunately it still doesn't work. The dealer told me they were unable to calibrate it as one of my tires is slightly smaller than the others(the full size spare is on the car right now). This really sucks as my nearest dealer is 200 miles away so I drove 400 miles round trip with no cruise and spent $430 dollars. They have agreed to re-do the calibration for free once I put on new tires which is good.

My question is this: Does the tire issue causing the ACC not to work seem feasible?

haggisuk

Completely believable, the radar can see cars upto 130 meters away a 1 degree deviation of the beam will be over 2 meters of mis-alignment at that distance.

In order for Audi to do a proper calibration your tyres have to be the same, and four wheel alignment carried out then calibrate the acc sensor.

Or you could tweak it drive it see how far out it is and tweak it again to fine tune it yourself

the_duke

Already tried the drive it an tweak it method. No luck. I can get it reasonably close and it will work for a few days but then the code comes back.

Tires are on their way. I bought super cheap Chinese tires by the way. That will make the service manager at Audi happy. He wanted me to put on a set of Continentals. Don't get me wrong Contis are awesome tires but I'm cheap and have had very good luck with Chinese tires on all my vehicles. They don't last as long or perform as well but when you get 75% performance/wear for 1/4 the price you can't go wrong.

I also ordered 5 new TPMS sensors.

Mister Bally

To each their own; I drive fast at times. I would not trust cheap tires at speeds the A8 is capable of. Are the tires you purchased rated to at least the North American Speed limited 130 MPH of your car?

Even if you normally don't exceed posted speed limits, there may be a time you are trying to outrun a tornado or something. I wouldn't want a catastrophic tire failure at that moment.

Believe me, I'm a cheapskate. Regular fuel 99% of the time. Mountain driving and my salt flats run, yes, the expensive fuel. Otherwise, goat pi$$ !

Jack88

Well, I wouldn't buy a Tuxedo and wear flip flops, but to each his own.

the_duke

I drive fast at times as well. Not so much worried about the tires as I am about the wildlife. The tires are 255/40ZR19XL so they are rated for speed and a heavy car. I've had really good luck with Chinese tires. They definitely don't last as long as good tires but for the price they are great. If I have a different experience with these I'll let you know.

the_duke

I can understand that. But you might buy an old thrift store tuxedo and wear it with flip flops to party. If I had the ability to buy a D4 I would put good tires on it. I'd also own some SRT cars and probably a Hellcat. But I'm just a poor Montana hick.