I've heard of some ITR guys running this size because tires are significatly cheaper. How many of you guys run this size?

recommend it? recommend against it? how off does it throw your speedo? your impression of the loss of 10cm, or anything else you can say about it?

 

You lose 19.5mm of diameter, or 1.95cm. OEM diameter is 595.5mm(195/55/15), the diameter with these tires would be 586mm. OEM Circumference is ~1871mm, the new diameter would be ~1841mm. That's a 30mm difference in circumference, or a 1.6% difference in circumference. This translates to your speedo saying you're doing 65mph, but you're actually doing 64mph.

Doesn't seem like a significant difference to me.

 

I run 205/50-15.
On a 15x6.5 rim.
I now have Kuhmo MX on my car and like them.

I would not use the 195/50-15 due to the weight rating/ safety.
But some poeple do...

 

I wouldn't do it. Go for 205/50/15's. They are closest to stock and will give a little more tread on the ground.