On Thu, 8 Dec 2016 20:37:59 -0000 (UTC), John Harmon wrote:

so a problem is how do I
convert the 2 minutes of accuracy to a plus or minus inch figure?

You need a cataly$t, and a good front end man. Bring your vehicle to the
front end man, lubricate him with your cataly$t ($100 should do nicely),
and he'll perform the conversion for you, even adjusting things to the
result you would desire (key word or phrase: "wheel alignment").

HTH. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.