Hello,
I need to replace my tires. My car currently has the stock optional 17" wheels with four P225/45R17 tires. My question is, can I put the wider 255/40-17 on the rear tires? Or do i need to get all four replaced with the P225/45R17 tires? I'm not sure if the wheels in the back need to be bigger to use the wide ones..
Go big. Not sure why you would stop there unless your rim won't support more. I am running 275 on my E92, and 245 front.
Wider tires look way cooler. I also have 275 in back and 245 in front. They run great and are fun as heck! I decided to get a cheap brand and try it out for the first time. Nankang ns-ii. Mostly for drifting than anything else, but surprisingly good for daily also!
okay I'm just going to get new wheels. Staggered 8.5 front , 9.5 rear. Or should I just get 8.5 all the way around? The benefit being that I could rotate them equally... If the only benefit for staggered is looks I'm thinking it may not be worth the long term costs.
Also, how do I know what size aspect ratio to choose for an 18" wheel? It seems the 245F/275R is standard for a stagger but I cannot seem to figure out what the aspect ratio (middle number) should be?
Thanks
Thanks, I actually called them today but they weren't much help because they do not source the wheels I want.... I ended up getting some good advice from a local Discount Tire here. I decided to go with staggered beyern spartan wheels- 8.5 front tires 245/40/18 , 9.5 rear tires 265/40/18. They said this tire size would fit well. I was starting to learn toward 19's but just can't commit because of practicality and additional costs of replacing the tires. I do not plan on lowering my car fyi. Now that I have the size down I just need to pick a good tire. I welcome any recommendations.
Just make SURE that the diameter of tires front and rear is the same! Don't tear up your X drive.
You can check tire diameters and revs per mile on the Tirerack.com site by looking up the tire model you plan to use.
I don't have X-drive, does that make a difference? Over all diameter for Continental Extreme Contact DWS Tires show 25.7 front/ 26.3 rear for the tire sizes I listed above, is that close enough?
That is what the employee from discount tire told me would fit w/ the wheels I want and "look good" with a higher backend staggered look. Honestly I'm lost when it comes to tires so I was just looking for the widest tires I could fit without any rubbing issues, while still having a comfortable ride. So your saying it may rub in the rear while those sizes?
There's a chance it could rub. Generally the tire width is the issue (a 265 is fine), but going a full 1" taller may cause problems. However, if Tirerack said it will work, then I would think you can trust them.
Sorry to bring up an old thread but I wanted to ask everyone who runs F245/R275 a question. Does this mess with the accuracy of your speedometer?
Running a 245/275 with the tire I'm going to get would put me at overall diameter 25.7/25.6, 808/811 revolutions per mile, which is pretty close.
But when I used the wheel offset calculator on bimmerpost I got 2.893% difference for the 245 front tire from my oem setup. And putting a 275 on the rear only put me at 1.689% difference. Is the 2.893% too much?
Maybe I'm just nitpicking but I guess I'm wondering if I should just go with a 235/265 to be safe and not stray too far outside the 1-3% recommendation. BTW this is a RWD car not AWD.
Thanks,
Lucas
Any time you change to diameter of the tire, you change the accuracy of your speedometer.
My speedo had the normal error of reading 3-4 MPH higher than actual speed; when I run my snow wheels/tires, their diameter is just enough larger that the speedometer becomes accurate!
You can bet that the next time I need street tires, I'll work the same trick with them...and very much on purpose. BMW is very consistent about having their speedometers indicate a higher speed than the vehicle is moving.
Incidentally, you can download apps for your smart phone that will use your GPS system to show your *actual* speed - which you can compare to the speedo reading. I use one called DigiHUD on my Android phone.
Old thread, but reading it for research and replying in case other read as well.
BMW speedo will show 4 kmph over actual, intentionally.
This can be coded out so it reflects accurately as well, though I prefer the 4 kmph over.
Clearly tire circumference affects the actual speed as well. Oodles of calculators online.
That said, I'm currently migrating to f245/40/18, r275/35/18. I have X1 322 wheels (9" rear) and really hoping (also expecting) them to clear!
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