[MichBadger]

I'm shopping local Craigslist for a set of winter wheels and tires for my 2017 M240i. I really don't have any idea how to tell if these would fit on my car. From reading here, it sounds like clearance to the brake calipers is the issue.

#1 option
What I think appear to be MSW Type 14 wheels off of a 2013 X3 with Michelin Latitude 235 60R17 tires.

#2
16x7.5 Sport Edition A7 wheels with 205 55R16 Dunlop Graspic D3 tires.
I'd expect this to be way too small but it says they came off of a 2015 230i, so I thought maybe there's a chance.

Any idea if either of these would work and how I can tell in the future? I'd really like to go with 17" wheels instead of 18" to help with pothole damage avoidance.

[dradernh]

#1 The tire is too tall by almost three inches. This is how I determined that:

(235*0.6/25.4*2)+17 = 28.1"

235*0.6 = how tall the tire is above (and below) the wheel
/25.4 = convert that height into inches
*2 = double that height (to account for the part of the tire sitting on the ground and the opposite part of the tire)
+17 = add the diameter of the wheel to the two tire heights
28.1 = the diameter of a 235/60-17 tire (roughly)

Our cars generally run tires right around 25.0" in diameter.

#2 The diameter is fine. I don't know if a 16" A7 wheel will fit. I'm guessing not as Tire Rack doesn't show 16" options for your car, and I believe that the A7 is their wheel (i.e., they have it manufactured and would be happy to sell them to you - if they would fit).

"how I can tell in the future"

You can go to the Rack's site to find out the diameter of a tire; if it's within .4-.5" of the size BMW put on your car at the factory you should be good to go. You can always call the Rack, too, as they know pretty much everything there is to know about fitting tires and wheels onto cars. They'll help you whether you order from them or not.

Beyond finding out ahead of time if the diameter is too small or too large, and being advised by experts like those at the Rack, the bottom line on fitment is that you must put the mounted tire on your car to know if it will fit.

[MichBadger]

Thank you very much for answering the question with so much detail. By you giving the formula and then using Google, I realized that my understanding of tire sizing was completely wrong.

My car currently has 225/40R-18 which gets me to almost exactly 25" total diameter, as you state.

I just found a set of 205/50-17 with Goodyear Ultra Grip GW3 tires. From doing the math, it would seem these would be almost exactly the same diameter and might work depending upon the ID of the Sport Edition A8 wheel. I can call tire rack on this.

One of the photos shows a possible slice in the sidewall but no mention in the ad. Assuming this tire hasn't been "knifed", should I be concerned about this?

Also, from a value standpoint, I don't have much experience buying a used set of wheels and tires? Cheapest possible new wheels with decent winter tires appears to be in the $1200-$1500 range for a set of 4. Is $500-$700 an average price for a set with decent tread left on them.

Lastly, am I being ridiculous if I'd want to take the set to a tire shop and check the balance before purchase?

[dradernh]

Originally Posted by MichBadger

One of the photos shows a possible slice in the sidewall but no mention in the ad. Assuming this tire hasn't been "knifed", should I be concerned about this?

Also, from a value standpoint, I don't have much experience buying a used set of wheels and tires? Cheapest possible new wheels with decent winter tires appears to be in the $1200-$1500 range for a set of 4. Is $500-$700 an average price for a set with decent tread left on them.

Lastly, am I being ridiculous if I'd want to take the set to a tire shop and check the balance before purchase?

For used tires, I always recommend looking at their dates of manufacture and measuring their tread depths.

For a winter tire set that's going to be used with snow or ice on the ground, I have two rules of thumb for replacement:

1) Replace the tires at 6/32nds tread depth; and/or,
2) Replace the tires approx. four years after their date of manufacture.

The first is so that the snow still has somewhere to go, enabling the tread to work its way down to grip the surface of the road (or the ice). The second is that winter tires are effective when their rubber is still very soft, and the older the tire the harder it gets.

I came to these conclusions during the couple of decades I lived in Northern New England. Other drivers will likely have come to different conclusions.

Regarding the GW-3, it's performance winter tire, and all of my experience is with conventional winter tires. That's because in NNE I was guaranteed to be driving regularly on snow and ice each winter.

My understanding of performance winter tires is that they're oriented more towards dry road performance when the temperatures are below freezing. I've assumed that as a result they give up some amount of absolute grip on snow and ice, but I can't say that from experience. Note that the GW-3s you're considering are quite narrow at 205. That's fine for cutting through snow to get the rubber down on to the pavement, but probably not ideal when it comes to dry road performance driving.

----------------

I really can't say what that cut in the tire is about. It wouldn't hurt to have someone you can rely upon take a look at it in person. Maybe an independent, non-tire shop that you trust?

Yes, $500-700 is a typical price for sets of winter tires with some miles on them and when they're mounted on inexpensive wheels. Expect to pay more for BMW or BBS wheels.

As an example, outside Detroit I paid $750 for a used set of BBS SR 17X7½ ET35 wheels with 225/45-17 Michelin X-Ice Xi3 tires on them. The tires had an average of 8/32nds of tread depth. The wheels had a fair amount of scrapes on the faces of the spokes on each wheel. The set came with TPMS, and it cost the previous owner $1800 from the Rack.

FWIW, in the winter I drive my car only to fully warm-up its drivetrain. I do that with a two-hour drive every three or four weeks. I drive it only on dry roads in the winter.

I don't see anything wrong with wanting to have the balance checked-out before buying a set of mounted used tires.

[MichBadger]

Thanks again for another detailed response. I've lived my entire life (I'm approaching rookie old guy status) in Wisconsin and Michigan and never owned a set a dedicated snow tires. I'm truly more concerned about the potholes hiding under the snow than I am with the added traction. I bought x-drive for that reason, since I was committed to making this my daily driver. If the snow is too deep, I have the option of working from home most days. I've recently replaced two wheels from pot hole damage which is also something I've never had to do before owning this car. The expense of that was more than a used set of winter wheels and tires should cost me.