Tires/2004 BMW X3 2.5i SUV
My vehicle has 235-55R17 all season tires and I want to buy 4 snow tires and then another set of all season or summer tires with a longer life than the last set I bought (19,000 miles)! I have read that snow tires should have less contact with the ground so more weight/tire is concentrated on a smaller area/tire which would help traction. So what tires sizes would best accomplish this out of the following, ranked in order of superiority/preference?
Are any of these sizes undesirable for my vehicle for other reasons apart from the footprint issue? I would have thought there would be tables on the internet that would set this out but perhaps my understanding about footprints is incorrect. Thank you very much for your time and consideration. John
I'm a little confused by your question, because you've included in your list of 4 sizes, 2 sizes that are wider and would therefore have a larger footprint - and the only narrower tire that fits on your wheels is 225/60R17.
But the big issue is that careful selection of a tire has many times the larger effect than a simple tire size change.
Put another way, using the original tire size is not as big a deal as selecting the right tire for the job.
---------- FOLLOW-UP ----------
QUESTION: Thanks very much, Barry. What you told me makes a lot of sense. I should have done a little more homework before confusing you with a poorly worded question. In any case, how did you know that the 225/60R17 was the only smaller tire I listed that would fit my vehicle? Are there other tires out there of smaller size than the 225/60-R17 that would also fit my needs? And how does one find this info out? I figure that I might as well nail down this part of the equation and then follow up on your suggestion re other attributes of winter tires I should seek out/! And what are your suggestions for finding the right tire for the job? The job is to find a tire that wears well and is pretty good on both snow and ice.
Gee, if I told you all of those secrets, you could be answering these questions and I would be looking for work. Wait, I don't get paid for this.....
OK, first, how do I know what fits? Discount Tire has alternative fitments listed on their website. I know they check these, but their problem is they don't check on wheel widths.
Stock wheel widths? Tire Guides publishes a series of books that have that info.
Then I check the load carrying capacity to make sure it is not going down (I'm not sure Discount Tire does that!) Ergo, a 225/60R17 is the only tire that makes the list.
Second, my expertise is in the engineering part of tires. I can't keep up with all the changes that take place in the marketplace, so I don't even try. Plus, my former employment with a major tire manufacturer kinds makes me biased = and I don't think it is fair for me to express opinions on other brands.
As an aside, I know there are all season tires that do extremely well with wear AND snow traction. They give up some grip to be able to do that. Are they as good as a summer tire / winter tire changeover? No, but that's the point. You don't have to changeover.