by Gipsy on Sat, 12 Jan 2019 9:27 +0000
My calculations show standard size is 30.56" diameter and 70 series is 31.56" so just 1" taller diameter. Now if you want to calculate the circumference of each tyre it is 3.141 multiplied by diameter. This gives a difference of103.2% larger for the 70 series. Therefore your spedo will be more accurate because the standard tyres give Speedo around 97% of true speed.
Oh before the 'experts' jump in.... I did say SIMPLE calculated size. I just measured my 265*70 standard tyres with 58ks on them and got 750mm or 29.52" so the calculated size is reasonably accurate if you add around 1/2" tyre wear!
And also remember the 265 is millimetres so you must convert to inches! 265mm and the rim is 17" just to confuse us all
Last edited by
Gipsy on Sun, 13 Jan 2019 4:42 +0000, edited 2 times in total.
Cheers Gipsy
although I'm sure somebody will challenge that
even Einstein wasn't certain of his theories.
My 2013 auto D4D DC SR5, prefilter, 3" exhaust and Chip with egt probe, stock SR5 rims with Toyo Open Country AT2 265/65R/17's