[rohan_b79]

I have a 2011 X3 35i that came with summer run-flat Conti SportContacts SSR as OEM in staggered configuration F:245/45/ R19 R: 275/40 R19.

I want to replace them with M+S rated tires, and thinking about the Conti Extreme DWS or pirelli Pzero Nero. So my question is, can I put the same tire size on all 4 wheels i.e. 245/45 R19? Or is the wheel width of the rears different and I have to stick with the staggered size M+S tires?

[brissim]

All four tyres (tires) must have the same outside diameter. The two tire sizes of the staggered size have much the same outside diameter (according to my sums 703.1 mm and 702.6 mm respectively), so its up to you which way you want to go.

Tony

[brissim]

rohan - sorry - I think I may have fired off my previous post a bit too quickly. What in fact (I think) you are asking is whether a 245 wide tire can be fitted to the rear wheel which I assume has a wider rim width to accommodate the 275 wide tire. Don't know off hand - I would talk to your tire retailer for the M+S tire and ask them what is the recommended range of rim widths the 245/45 19 can be fitted to and how does that compare with the actual rim width of the rear wheel.

Tony

[rohan_b79]

Tony- Yeah you got it right the second time .

what I want to know is basically if the rear wheel width is the same as the fronts when your OEM tires are staggered? And even if its not then is it possible to put same size tires on all 4 wheels rims i.e. 245/45/ R19.

The BMW dealer here could not give me a conclusive or convincing answer. Has anyone tried putting All season tires on their 2011 X3 that came with 19" staggered tires initially?

[Nahoa]

The rear wheels are wider when staggered, it's not just the tire. I don't believe you can put a smaller tire on them. For example, I couldn't put the "one size" Pirelli Sotto Zeros on the staggered wheels for the Winter (they weren't available in 270/40/19). Ended up getting at set of 245/45/19 wheels to accommodate the tires.

I haven't been able to find any All Season RFTs that fit. Would love to put on P Zero Neros, but not available.

[Polar_Bimmer]

If it helps, tire size calculator:

http://www.1010tires.com/TireSizeCalculator.asp

[GenX3]

I've often heard of the "Plus size" tires, meaning, you can get a slightly larger tire on a particular rim (both aspect and width). I would have guessed the converse would also be true. If you look at the calculator Frank linked, it would suggest that 245/45/19s could go on a rim/wheel width range from 7.5" to 9". The surprising thing is that 275/40/19s go on rims ranging from 9.5" to 11". Suggesting that the very smallest width of your rim is 9.5".... and you couldn't, therefore, put the 245/45/19s on there because the rim width is too wide.

LOL, I had the opposite problem. I wanted to stagger my tires (I have 245/45/19 all around). The math doesn't work for me either. I'm gonna stick with what I have... suggest you do the same.

[rohan_b79]

@GenX3
Thanks for pointing that out. I took a look at the calculator, and found more interesting stuff, that contradicts the width range specifications as given by the calculator itself.

Ok check this out -->
For 275/45 R19 it says the tire section width is 10.82" (rim/wheel width range from 9.5" to 11"), so 10.82 falls in between the range given in parentheses.
However, for 245/45 R19 the tire section width is 9.64" (rim/wheel width range 7.5" to 9"), so here 9.64" falls outside the range given in parentheses. More confusion

Kind of disappointed with the fact that a meticulous German brand such as BMW does not have sufficient and has skipped tire information and the product itself for discerning customers.

[GenX3]

That is peculiar about the tire width falling inside/outside the wheel width. I did a quick search on the 2011 wheel sizes and would guess that your wheels are 19" x 8.5" (part number 71478) in the front and 19" x 9.5" (#71479) in the back. "Offset" is another element that might cause a very minor visual concern. In that the back wheel might sit too far inside the fender (negligible I'm sure)... But there is a difference between your front and back wheel offset to make the staggered wheels lineup with the fenders.

Grass is greener on the other side, eh? You have what I was after, I have what you were looking for.