Quote:
Originally Posted by haigha
Interesting! I've been running a square set of 275/40R20 on my E53 for about 15 years with about 24k miles on the odometer after switching them. No re-coding was done.
I used this site:
https://tiresize.com/height-calculator/
to calculate:
275/40R20 is 28.7" tall (diameter), 90" circumference, 704 revs/mile
255/55R18 is 29" tall, 91.2" circumference, 695 revs/mile (my original wheels were Style 74 18")
So does that mean my odometer is overstating the mileage by (1 - 695/704) * 24k, or about 307 miles? |
I'm not saying recoding is necessary to run different tire sizes...the DSC will not be able to know that unless its parameterized. I am implying that the speedometer will be off more/less than the typical 3mph that BMW purposely does. But that's a good point with the revs/mile. It looks like it'll be off slightly more than 1% difference. It's on my todo list for checking the coding because I thought I saw an option for performance tire size.
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2003 BMW X5 3.0i -- MT5, 3.64s final gears, H&R lowering springs, K-Mac bushing kit
2007 BMW X3 3.0Si -- MT6
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