Originally Posted by M3 Esq.
Based on researching manufacturer specs on tire rack, the largest recommended size is usually 255 on an 8.5 wheel. Not sure I would be comfortable going to 265 unless it was within the manufacturer spec.
255 is the largest recommended for an 8.5, but seems like many people with other cars have run 265s without any problem.
Try a google search....lots of pics and info on the subject.