So, my speedo was dead-on this winter when I used a set of 740 snow
tires and wheels (195/65R-15, giving a diameter of 25") on my car. I
was going to reinstall the summer tires yesterday, but I noticed
that they were much smaller. The tires are Continental 185/70R-14s,
with a total diameter of 24.2". This is the correct size for the
sedan and not the wagon, which is supposed to use 185/R-14s (.82
aspect ratio, total dia. of almost 26".


So, it looks like the tire shop (STS) screwed up when selling me
tires last year. I should have checked, but then again, I was a
Volvo noob at the time. As long as I don't explore the upper limits
of my wagon's load capacity, is there any harm other than speedo
error and slightly higher engine revs of leaving the incorrect
tires on? Did anyone have the opposite mistake happen to them,
and wants to trade? :)


TIA -b.