2016 maxima tire is 245 40 19 , would 245 45 19 fit, any issues?

 

No issues I can see. Speedo should remain correct.

 

I can't speak to any clearance issues but going from 245/40-19 (on a 8.5" wide rim with a 50mm offset) to a 245/45-19 does the following:

• The external wheel diameter goes from 679 mm (26.7") to 703 mm (27.7") which is a 3.5% increase
• The tire circumference goes from 2132 mm (83.9") to 2207 mm (86.9") which is a 3.5% increase

As such, the actual vehicle speed would be 3.5% faster than the speed indicated on the speedometer. The car would really be traveling 62.1 MPH at an indicated speed of 60 MPH...

 

Well thought out answer posted here. I did however swap a set of EBay 19 inch 2017 Nissan Maxima wheels (not rims) and the 245X40s over to my 2016 Platinum with no ill efects. Speedo was verified with Garmin GPS and was within 1 MPH of actual speed @ 70 mph. Go figure

 

that’s because the 245/40/19 is the OEM diameter. So it’s the same as your 245/45/18

As for OP’s question, 245/45/19 will rub quite a bit up front on full wheel turn.