mjsbth

Hi all,

I'm new to the forum and very happy to have found it.

I have a 2015 A8 4.0 L that witha stock tire size of 265/40/20. I live in a part of the country that gets real nasty in the winter and I'm on a lot of dirt (i.e., ice) roads all winter long. I've been running variations of the Nokian's Hakkapiliitas (studded) for some years. Best I could find for this vehicle are the Hakk 9's in a 245/40/20. My options for snow tires in the stock size, and even in 255's, are not up to the task of what I need.

I realize putting on 245's will probably affect the accuracy of my speedometer. I don't really care about that, and can figure it out/adjust. My only concern is safety.

Best I gather, they will fit, and there are no safety hazards to using this size. It would be a safety hazard for me to run less than optimal snow tires that aren't studded.

Anyone have info on other associated problems with going this route, or if it in fact would be unsafe? Tire guy I spoke to who's selling the Nokians seemed to think there's no safety issue, but I just want to get some feedback from more than one person (that person being the guy trying to sell them to me, no less...).

Thanks!!!!

Glisse

It is not so much the width of the tyre (245mm) that is the issue. It is the height of the sidewalls - OEM sidewall height is 40 percent of 265mm, and you are planning to reduce this to 40% of 245mm. The speedo difference is only around 2%. But you are going to suffer in ride quality and increase risk of damaging the wheels running the lower profile. You are also putting a narrower tyre on the same 9" wide wheel, so the tyre is a little stretched, which means the sidewall is under more stress. But probably not a big deal for any of these issues, just pointing out what you are affecting by the change. Which is more than the speedo (and odometer) being a bit out.

A 245/45/20 would be closer to OEM, and Nokian do make the Hakkapeliitta 9 studded in that size. For that matter, Michelin do make the X-Ice North 3 studded in 265/40 R20.

Given your description of your winter conditions, I'd be very tempted to use OEM 18" or 19" winter fittings, some of which can also accommodate the use of chains for when the studs aren't enough. But can understand you mightn't want to buy another set of wheels.

You might also want to check in the D4 A8 forum to see what others are using, although most are not driving an A8 in your conditions, I suspect.

mjsbth

Thanks so much for your thoughtful answer, Glisse! I have not mounted them yet, so I am going to see if I can trade them back to the tire dealership for the 45 profile. They appear not to have that size in stock, but perhaps I can order them. I think you are saying there is no real safety issue (aside from potentially damaging my rims), which is my big concern. Thanks, again!

mjsbth

They DID have the 245/65/20 in stock! Swapping them out. Thanks, Glisse!! I feel much better!

mjsbth

Meant to say 245/45/20

Glisse

Good result on finding the 245/45 - enjoy the winter!!