Re: What about 235/35x19 tyres - anybody fitted them as alte
Simply speaking, changing from 40 series to 35 series means basically that you have less sidewall. Benefits - less sidewall movement for less body movement on the tyres, better for cornering. Disadvantages - closer to the road which equates usually in more noise transferred into the car, and you will feel more bumps in the road.
Going wider and staying with 40 series will give you more sidewall and reducing noise and feel.
235/40/19
235 = tyre width (not tread width)
40 = % of tread width is sidewall
19 = tyre inner diameter
Overall tyre diameters differ based upon changing the width and sidewall %. You can find some wider or taller tyres that have close to what you have now without it affecting your speedo much at all. For example:
235/40/19 = 26.4" diameter and 787 RPM's (Revolutions Per Mile)
245/35/20 = 26.7" diameter and 777 RPM's
Note: different tyre manufactures may have different results for diameters etc., the results I have provided are for the MPSS's. Tread depth will also apply. The MPSS's are a High Performance Summer tyre with a 10/32" tread depth. The same size but All-Season model will have a larger diameter because tread depth is greater. Also you may find the same tyre size within the same manufacturer and model of tyre and yet they may have two versions. For example the 245/35/20 MPSS has a version with 9.4" tread width (found on Ferrari's) and another version with 8.5" tread width. The 8.5" means the tyre curves in more at the edge allowing for fitting them into tighter areas.