Advice on 18x10 / 18x8 rims and tires for 99 Boxster

[Jasper_Boxst]

Looking at some different rims for my 1999 986. I came across a set of 2003 5 spoke with tires.

The rim sizes are 18x8 front and 18x10 rear
The tires are 225 40 18 fronts & 285 35 18 rears.

I currently have the stock 17" twists installed. With these sizes, would I need spacers and if so, what size?

Would I be better off with smaller tires in the rear? And lastly, would I need to change camber or anything of the sort with wheels this wide?
By the way, just for street driving.

Any ideas?

[JayG]

Spacers will depend on the wheel offsets
Standard 18's are 265/35 rears

[Jasper_Boxst]

Thanks JayG. For the rears, the wheels are a 65mm offset. I'm thinking 20mm spacer or even 25mm?

[KMikkelsen]

I have these tires. And I calculated that I needed a 35mm spacers in the back.
There are some calculators online for it.
Can't remember how much in front.

I decided to buy some others and my set is for sale at the moment.

/Kim