Useful Tire Spec Calculator
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Useful Tire Spec Calculator
Hi, All. I have been trying to decide how to equip my 2015 GT PP with winter tires. I have decided I am going to pop for a new set of wheels and tires and store one set offsite over the off-season. With the wheels and tires I want, this will cost over 2 grand. Oh, well. You can't take it with you!
I found a utility that really helps to determine what sizes can be used for various rim widths, diameters, etc. Also, from this utility, I see that I can put 255/45R19 on both the 9" fronts (stock 255/40R19) and 9.5" backs (stock 275/40R19), and this size will keep me within 1mph of the speedo calibration.
A question would be can I rotate the 9.5" rears to the front and the 9.0" fronts to the back... Food for thought.
Here is the website: http://tire-size-conversion.com/tire-size-calculator/
Let me know what you think.
I found a utility that really helps to determine what sizes can be used for various rim widths, diameters, etc. Also, from this utility, I see that I can put 255/45R19 on both the 9" fronts (stock 255/40R19) and 9.5" backs (stock 275/40R19), and this size will keep me within 1mph of the speedo calibration.
A question would be can I rotate the 9.5" rears to the front and the 9.0" fronts to the back... Food for thought.
Here is the website: http://tire-size-conversion.com/tire-size-calculator/
Let me know what you think.
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I wouldn't recommend rotating staggered sizes front-back. Most shops will probably discourage this if you ask.
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An alternative would be to swap the tires but not the wheels from front to back. I think this would be about $20 per tire, but would you need to add the TPMS renew kit?
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My favorite is this one:
http://www.rimsntires.com/specspro.jsp
It gives you the info and diagrams too. Sometimes it's helpful for comparison to see how it is going to be oversized/undersized or backspacing issues, that sort of thing.
It may not be as technical as the other one, but this one is dynamic and for most is probably a little easier to deal with.
Nothin' wrong with that other, just... I like shiny and easy.![Smile](https://themustangsource.com/forums/images/smilies/smile.gif)
In case that helps anyone!
http://www.rimsntires.com/specspro.jsp
It gives you the info and diagrams too. Sometimes it's helpful for comparison to see how it is going to be oversized/undersized or backspacing issues, that sort of thing.
It may not be as technical as the other one, but this one is dynamic and for most is probably a little easier to deal with.
Nothin' wrong with that other, just... I like shiny and easy.
![Smile](https://themustangsource.com/forums/images/smilies/smile.gif)
In case that helps anyone!
![Thumb](https://themustangsource.com/forums/images/smilies/thumb.gif)
Last edited by houtex; 3/21/15 at 03:49 PM.
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Oh, I like yours much better! I will have to spend some time with it. Thanks! I especially like the way it does offset. Do you have the specs on what the offset on the pp wheel is?
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If you are talking about this wheel, well, it says it's 52.5mm offset.
But that's the 9.5" wide wheel. If you are talking the 9" wide one, then that's 45mm.
But that's the 9.5" wide wheel. If you are talking the 9" wide one, then that's 45mm.
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Indeed, it would be better to get two more rims (19 x 9) for the winter tires and run them along with a tire swap on the 19 x 9 rims already present if rotations are under consideration.
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Well, I am torn, but this is what I am going to do. I am going to get a set of the silver performance pack wheels from Ford Racing (m-1007-m199s and -m1995s) when they are released, it says 5/15/15, and order a set of michelin pilot alpin pa4s from discount tires (4 of the 255/45R19s). Because I love the silver with the Ruby red.
I will have discount remount the OEM summer tires on the silver FR wheels, and have the michelins mounted on the black OEM pp wheels for the winter. Then store the offseason ones each season. I would love to trade the black pp wheels for some 50th anniversary wheels, but it just seems too complicated.
The 255/45R19s will just fit on the 19x9.5 rims (thanks to houtex's calculator) so I can rotate them eventually (tires only, but not wheels) if I want to. Fun project to keep me busy while I wait for my (hopefully) 4/10 delivery...
And I am a little concerned because the calculator shows there is only 1/4" of tire projecting beyond the 9.5" wheel rim...
I will have discount remount the OEM summer tires on the silver FR wheels, and have the michelins mounted on the black OEM pp wheels for the winter. Then store the offseason ones each season. I would love to trade the black pp wheels for some 50th anniversary wheels, but it just seems too complicated.
The 255/45R19s will just fit on the 19x9.5 rims (thanks to houtex's calculator) so I can rotate them eventually (tires only, but not wheels) if I want to. Fun project to keep me busy while I wait for my (hopefully) 4/10 delivery...
And I am a little concerned because the calculator shows there is only 1/4" of tire projecting beyond the 9.5" wheel rim...
Last edited by Salguod; 3/23/15 at 08:22 AM.
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I must admit, I don't know why you're going through all that trouble to get the different wheel sizes but the same tires. o.0
I'd get the 9s or the 9.5s They will both work, as I have the 9.5" wide GT500 rims. No issues. With a 1" drop, admittedly, but looks to me that a 1.5" would also be fine.
I also have 275/40-18s on my rims, all 'round, and no rubbing issues. So unless you want the look of the GT500, which is 255/45-18 up front, 285/40-18 in back, you can get the 275 wide for all four. 275/35-19s I think, but check the calculator against stock, of course. Or mine, the 275/40-18s, 'cause if you match that width/height, you'll be good.
That way you can just swap them about no issue (unless you have directionals, like me, that will require you to dismount and remount to swap left to right, but back to front is ok.)
Just food for thought for ya.
I'd get the 9s or the 9.5s They will both work, as I have the 9.5" wide GT500 rims. No issues. With a 1" drop, admittedly, but looks to me that a 1.5" would also be fine.
I also have 275/40-18s on my rims, all 'round, and no rubbing issues. So unless you want the look of the GT500, which is 255/45-18 up front, 285/40-18 in back, you can get the 275 wide for all four. 275/35-19s I think, but check the calculator against stock, of course. Or mine, the 275/40-18s, 'cause if you match that width/height, you'll be good.
That way you can just swap them about no issue (unless you have directionals, like me, that will require you to dismount and remount to swap left to right, but back to front is ok.)
Just food for thought for ya.
Last edited by houtex; 3/23/15 at 09:01 AM.
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Thanks for your detailed input, houtex. I am not clear on what you are suggesting, however. To clariffy my situation, I will have the black pp wheels and tires to start, of course. I am sold on the idea of separate wheels and tires for winter.
I like the looks of the FR silver pp wheels a lot, so needing that second set of wheels, I thought I would get the silver staggered FR wheels and use the staggered OEM tires on those for summer. I would use the black wheels and get the same size winter tires to put on those. I could get staggered tires but I think the wider tires in the winter are the wrong way to go and the wheels will (just) handle the same tires as front. And the wider ones cost more.
But I do want to keep the same height, by the way, to keep the speedometer in cal.
If I was sure I could sell the black pp wheels, I would get some maybe AMR silver 19x8.5" wheels and maybe the 245/45r19 x-ice xi3 michelins to save money, but that is so much more trouble. To go to craigslist or something to sell the black wheels for how much, etc....
Do you see another way to do it?
I like the looks of the FR silver pp wheels a lot, so needing that second set of wheels, I thought I would get the silver staggered FR wheels and use the staggered OEM tires on those for summer. I would use the black wheels and get the same size winter tires to put on those. I could get staggered tires but I think the wider tires in the winter are the wrong way to go and the wheels will (just) handle the same tires as front. And the wider ones cost more.
But I do want to keep the same height, by the way, to keep the speedometer in cal.
If I was sure I could sell the black pp wheels, I would get some maybe AMR silver 19x8.5" wheels and maybe the 245/45r19 x-ice xi3 michelins to save money, but that is so much more trouble. To go to craigslist or something to sell the black wheels for how much, etc....
Do you see another way to do it?
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