Porsche Enthusiasts Club Forum

Hello all,

I need to replace the rear tyres on my 89 LUX which has 15" teledial rims.

The current sized tyres are 215 60 R15 however I am struggling to find much choice in this size.

Would it be advisable to change to say 205 60 R15 instead where there are plenty of tyres in this size? The rolling radius is also fairly close - around 1%?

The fronts (from memory) are 195 65 R15 so by reducing the width on the rear would result in a more "square" set-up - is this preferable based on your experience?

Thanks,

Oliver

using 205/55/15 on my 931

205/60R15 will be fine . Another choice could be 225/55R15.

I use 215/60/15 and agree there is little choice but my firestone tyres have been very decent and at £75 a corner they're good value.

Your car would have had a "square" set-up from the factory. Only the 944 S2 and 944 Turbo came as standard with staggered tyre sizes. Original size would have been 195/65 R 15 all round or 215/60 R 15 all round if option M164 was specified.

Or put the 195/65/15 on the rear there's a better selection in this size also. Goodyear Efficient grip Performance are very good wet, Dry and comfort.

R

They should have the same size of tyre fitted to the back as to the front. Id fit 195/65/15s all around, or 205s, but not a mixture.

For reference, all but the very earliest 944s came with `195/65/15 tyres as standard, with 215/60/15s offered as a frequently taken option.

Whilst staggered option wheels had been available for 944s from the outset, these were always a compromise, comprising of 911 wheels and tyre sizes...

One final point: the 944 Turbo was developed on 7"x15" wheels, and only received 7" & 8" x 16" as a boost from the marketing department.

[quote="morghen"]using 205/55/15 on my 931

This incorrect size is over 4% smaller Diameter and will lower the ride height by 1/2",
change the Speedo accuracy and use more fuel etc...

R

That's correct, its incorrect if you want to stay within factory specification, the size I use is smaller but it also looks less ballooned...less ready to go offroad and a tad more fresh and sporty...also a bit less wobbly on the corners and crisper turn in.

I'm going to use 195/50/16 tires on my 931(smaller by 5.2% compared to factory, lowering the car by just a bit over 1"), the 944 may look like it needs bigger tires though with the more bulky tires..but I don't think it will look more goofy than how it looks with the factory prescribed tires.

That's Life isn't it, since the 80's the emphasis is for wheels to be Big is best, side profiles need to be smaller...

Marketing and car's have been sold like this for decades and there will always be a few that want to make an old car look newer or in their eyes less goofy or Un Kool.

I've tried lots and lots of combo's and I keep coming back to the narrowest Rims, narrowest tyre widths and higher profiles as this gives the best characteristics for Road use, Not track and not Looks but the best overall set up for road wet and dry use and with all the cambers, lumps and bumps out on UK public roads.

This is also with a stiff suspension set up, which makes it even more important to run with more profile as bigger wheels and smaller profiles effectively increase the spring rates and if they are stiff and modified too begin with this just's creates havoc...

The Myths that to get good handling you need low profile tyres, big wheels and wide tyre widths will never die!
But in my middle age i actually like this because "the boys" with their 19's can't work out work a 30 year classic with 195 tyres and 16's handles better!


R

Thanks for your replies.

I've gone for 195 65 R15 to follow the factory spec.

Thanks again,

Oliver

I just replaced my tyres. I wanted the spec 225 fronts 245 rears to replace the Dunlop SP900s - last and only chance for this spec was the PZeros the only size left in this country. Don't forget your pressures - 250 front 300 rear

Dave
S2

I'm guessing you have a 1990 model year S2 as that was the only one they specified that odd tyre pressure combination for.

I've always considered it too harsh at the rear unless you're on billiards table smooth roads.

Porsche changed their minds in the later workshop maintenance manual and specced 2.5 bar front and rear for the 1990 S2; 3 bar rear was noted as "optional".