>I have a set of OEM 2006 4.2 S-Type wheels.

Please let us know the size
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You dreamed of a big star -
He played a mean guitar -
He loved to drive his Jaguar...

So welcome to the machine

 

the tires are 235/50-17

 

I want to sell my stock wheels and replace them with 19" or 20" wheels, but I want the outer tire diameter to be at least very close to identical to what my car came with. It is a 2005 4.2 NA. What are my wheel/tire size combination options? I know the bolt pattern needs to be 5x108 mm, but I do not know the wheel widths, offsets or tire sizes that will work with each other and the car.

 

At the top of this page is a tab for "Tools". Use the Tire/Rim Calculator to match the diameter of the wheels you have to the wheels you want

 

It's an easy equation, e.g.: 225(width in mm) x2(top and bottom of tire) x .45(aspect ratio)=220.5mm/25.4(mm per inch)=8.68" + rim size, 17"(height in inches) and voila, you have your wheel/tire combo height. 25.68" tall.

Do it a few times and you'll memorize it. And you need to shoot for a combo size very close to the current overall height.

And if you have a 50 height aspect tire, you can eliminate the 'x2' step of course and just go with the width x ratio/25.4. Math can be fun!

Example for 235/50/17: 235/25.4=9.25" + 17"= 26.25, the original height of tire/rim combo. So, 245x2=490x.35=1400/25.4=6.75" + 19" rim =25.75 or 20" rim=26.75, both just 1/1" small or tall...