Wheel fitment question

[Pashets]

Hi All,
I’m new here, bought my 2001 Boxster S a couple months back and been thinking about upgrading its stock 17 inch wheels since then.
I came across used 981 18-inch ones a few days ago that come with good tires too, but even after checking the fitment in the tool linked here and on another site, I honestly still can’t understand if the new setup is going to work, and what I might still be missing, so would really appreciate input from experts.

Current setup 17”
Front: 7 ET 55; 205x50
Rear: 8.5 ET 50; 255x40

New setup I’m looking to buy 18”
Front: 8 ET 57; 245x40
Rear: 9 ET 47; 275x40

From what I understand, I’ll need 15mm spacers in the front. Is that correct?
Not sure about rear. Anything I should be worrying about in terms of the tires size?
Thank you all so much!

[redpepperracing]

Originally Posted by Pashets

Hi All,
I’m new here, bought my 2001 Boxster S a couple months back and been thinking about upgrading its stock 17 inch wheels since then.
I came across used 981 18-inch ones a few days ago that come with good tires too, but even after checking the fitment in the tool linked here and on another site, I honestly still can’t understand if the new setup is going to work, and what I might still be missing, so would really appreciate input from experts.

Current setup 17”
Front: 7 ET 55; 205x50
Rear: 8.5 ET 50; 255x40

New setup I’m looking to buy 18”
Front: 8 ET 57; 245x40
Rear: 9 ET 47; 275x40

From what I understand, I’ll need 15mm spacers in the front. Is that correct?
Not sure about rear. Anything I should be worrying about in terms of the tires size?
Thank you all so much!

This is my goto site for this stuff: https://www.wheel-size.com/calc/?wheel1=205-50-17X7ET55&wheel2=245-40-18X8ET57&fcl=50mm&wcl=30mm&scl=50mm&sr=0mm

That link has the specs of what you have on the front versus new, and yes, it looks a 15mm spacer would be ideal, as long as the fender still clears.

Here is the rear link: https://www.wheel-size.com/calc/?wheel1=255-40-17X8.5ET50&wheel2=275-40-18X9ET47&fcl=50mm&wcl=30mm&scl=50mm&sr=0mm

It looks like that should work with no spacer.

[Pashets]

Originally Posted by redpepperracing

This is my goto site for this stuff: https://www.wheel-size.com/calc/?wheel1=205-50-17X7ET55&wheel2=245-40-18X8ET57&fcl=50mm&wcl=30mm&scl=50mm&sr=0mm

That link has the specs of what you have on the front versus new, and yes, it looks a 15mm spacer would be ideal, as long as the fender still clears.

Here is the rear link: https://www.wheel-size.com/calc/?wheel1=255-40-17X8.5ET50&wheel2=275-40-18X9ET47&fcl=50mm&wcl=30mm&scl=50mm&sr=0mm

It looks like that should work with no spacer.

Thanks a lot! Will go check them out now I think