I have a thread with the exact same results.
stock 245/45/18 26"
now 245/50/18 27.7"
I run 45psi.
Always thought the stiffer tire would bother me. Not one bit, but I also have electronic suspension.
As a note: truck do not tend to have the same results.
Also: IMHO you need to have 50% of your driving at 'cruise speed' to achieve a payoff. Since a larger tire is slower to turn on start off.
EDIT: on the comparision that I did it was Kuhmo escta on both sizes.
Last edited by mcrews; 08-25-2012 at 12:19 PM..