Some designs of wheels just dont do justice.The stock wheels for example, offset +37 mm. From the center line of the wheel to the monting line should be 37mm, then if a 7" wide wheel like the saw blades has 177.8 mm. Divide by 177.8 by two thats 88.9mm, the centerline. From there, the wheel moves inward due to positive offset 37mm. If the offset really affects the wheel lip, then why the stock sawblades have no lip. Isnt 88 -37 =51mm or 2.1 inches of lip, Where is it at ?. After market wheels also do that in some cases.Take a look at the design of the sawblades, you ll figure out.
By the way tires are not a factor on wheel offset . They are bought on sidewall,wideness factors not on wheel offset, unless you know about what works on certain situations like low car or drag set up, flush or agressive for drift, ect ....and so on.