alex904

I'm totally confused. Tried to find cables suitable for 285/45-R20 run-flats and could not find them. Asked service representative at local dealership - he told me to look for low profile cable chain (regular chains are not suitable) and "they're sold at Walmart". Walmart, as all on-line stores don't have 285/45-R20 on the sizing charts. WTF!?
Also manual says that "285/45R20 cannot be fitted with chains". Very nice of Audi to put Euro high speed rims on US models and sell them in California where chains may be required in winter.
Just total confusion. No idea if I can put cables/chains at all and what size they're going to be.

Thanks!

CHIO

Don't be mad at Audi for this .. in Europe you have to have dedicated winters !! Can you just do that or does it have to be chains ?

alex904

Chains only. Caltrans and California Highway Patrol (CHP) define 3 conditions:
Caltrans Winter Driving Tips Winter Operations
Also National Parks have their rules and dummies that set R3 condition when it's not the case, but they still require ALL vehicles even with winter tires (even they're studded) carry chains. That's the case right now in Yosemite. Quote from the ranger: "If you can't carry chains, take a bus". So, 4WD specifically designed for off-road conditions IS NOT SUITABLE FOR DRIVING IN SUCH CONDITIONS according to CalTrans and National Park administration.

Winter tires are another catch 22. So, say, I buy those just for weekend trips. First of all, it's going to be a big waste of money as winter tires are going to die pretty quickly on bare asphalt and warm weather. Secondly, dummies at chain control points will still ask to put chains on or at least carry them in trunk.

And how not to blame Audi if they put rims for top speed 245MPH for cars sold in the state where you can get into jail for driving 100MPH?

tnedator

When I was researching low clearance cable chains for my Infinitit, these Z6 seemed to be very highly rated. They have one that will fit the 285/45R20

https://www.amazon.com/Security-Chai.../dp/B000HZFDQE

Some other places have them cheaper than amazon.

I never wound up using them in the snow on my infiniti, only put them on to try them out as it isn't required for me and I never had snow so heavy the AWD didn't cover it. I bought them in case I wound up hitting heavy snow on some trips I take to CO.

tnedator

Well, now I'm not sure. One site listed that as fitting 285/45R20, but in their fitment chart, they say 285/45R21

alex904

On top of that Q7 manual says "can't be equipped with chains" and most dealers make people sign the form confirming that they can't install chains on these rims.

tnedator

That sucks. Must admit I had planned on having a just in case set in the back in winter. The Zuper Z6 are ultra low clearance, but if the manual says it's a no go, might not be worth risking. I thought I previously saw a thread in here about chains.

alex904

Yep. I have to rent a car if I want to go to mountains. Q7 has enough of clearance for chains as far as I can see. So it's all about rims integrity then? And I can't change rims down the road as well. Audi has no alternatives.

tnedator

Just looked in the online manual and it says you can use snow chains on front tires, but it does have the disclaimer that snow tires only permitted on certain tire/rim combinations and to check with Audi dealer. Also says they need to add no more than 13.5 mm in height.

alex904

I've attached snippet from the manual. It's from 2015 model, but 2017 has the same clause.



So they put light weight rims which somewhat improves performance, but eliminated possibility of installing chains.