234/45 will increase the overall diameter much more than 215/40.
Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
215/40-17 3.4in 11.9in 23.8in 74.7in 848 0.0%
235/45-17 4.2in 12.7in 25.3in 79.6in 796 6.5%
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