When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I bought a consumer reports magazines on new cars, and I noticed that it listed the large turning circle (42 ft) of the C6 as one of it's negatives. So this made me wonder about the turning circle of the C5, but as I was researching this, I found one site listed it as 38.5 for the 1998 and a different site that listed 40.2 for the 2003. Then I found some other sites that listed lower than 42 ft for the C6. Are different groups measuring this in different ways? And did it actually vary (if the same method were used) between the 98 and 03? And how much lower a turning circle does the C5 really have compared to the C6 (if the same rating method was used)?
If you look at the largest to smallest you listed there is only like 8% difference, and only like 4% for the two different C5 numbers. Some probably rate the tire track and some probably rate the body track. But even at 4% that could be just the difference between cars. Many vehicles will have that much difference between left and right turns. My guess is most people won't notice the difference between the C5 and C6.
It is normal to see performance cars have a high turning radius. A small turning radius requires high turning angle on the front wheels and a short vehicle, much like you will see on a Subaru. Performance vehicles tend to have larger (wider) tires than most vehicles which tend to limit the turning angle because when these wide tires are turned sharp they will start to rub the body or suspension.
But it is easy to reduce the turning radius on the C5. Simply turn your wheels to the peg, rev up the engine and dump the clutch. It will spin around in a circle much smaller than a Subaru can do it!