For street I ride on 19" 8.5 front and 11" rear and will keep it like this.
As we are in between seasons I do some suspension work installing 996 GT3 LCAs and hopefully PSS10s coilovers if budget allows and also got into dilemma on what to do with tires. Alignment will be set preliminary to camber to -2.3 front, -2 rear, toe front 0.02 rear 0.10. Car is 997 C2, usage is 80% street 20% de/auto-x.

I would want to run next season on Toyos RA-1 but as budget is already quite stretched I wonder if it makes any practical sense to use stock carrera classsics 18" rims I have now - 8" front and 10" rear. Essentially it dictates using 235/265 tires.

All the people I know say that it does not make sense and proper way is to get 245/305 tires on 18" 8.5" and 11" wide rims or even may be 9" and 12". But as I have no money really left for that at all as even OZ Alleggertas cost $1.6K, Volks are at $2.4K, so, it will have to wait.

So what would be your opinion - will it make more sense to ride on street 19" PS2 tires on 8.5"x11" rims or on narrow 235/265 Toyos RA-1 on 8"x10" rims? Or would that be pointless waste of money as it will have even worse grip than wider PS2s on 19" rims?
Plus it is a bit confusing - I see that specs on different tires seem to indicate 10" wide rim can accommodate tires from 265 until 295? Isn`t any 295 tire too wide for 10" rim?

As of current moment I am not even as much concerned about my possible ranking position or fitment into particular class (was novice last season so there is still steep learning curve ahead) but about how to make cars` handling as much optimal as possible.

 

RA1s are better autocross tires than PS2s. Whatever grip you lose in width will be more than made up in unsprung weight reduction and lower rotating mass reduction. I would go with the 18"s but why limit yourself to 235/265? An 8" rim works fine with a 255 (that's what I currently use) and a 10" rim will work fine with a 295.

But if you are not concerned about class and have a limited budget then just buy what you can afford and what makes you happy. With your beginners skillset, the differences in grip are well within the "noise" of your ability. Were I you I would spend nothing on the car and invest in some driver's schools instead. Much better bang for your buck. And by waiting a year you will gain enough experience to better answer your own questions about future modifications and tire/wheel choices.

 

I am aware of this and actually agree. Unfortunately it is much easier to invest into car upgrades and get it done at the shop than find time to get away from family chores and have fun with car on a track.

Still, improved front camber was somewhat asked for based on my last year sessions. As of coilovers upgrade and other proper suspension rehaul for slicks may probably wait a year or so. Will see.

 

My first question is are you new to the track? If so, keep the car as simple as possible and focus on the learning. Larger and stickier tires are nice.. but they also hide mistakes.. and they can hide lack of skills. Save your money for "seat time".

 

Since you are posting this in the autocross forum I am assuming that by track you mean autocross. If you change your rim size to something not allowed in Super Stock (SCCA) then you end up in A Street Prepared or worse yet A Prepared. Coil overs on the suspension is an immediate upgrade to a higher class if my memory is correct.
The tires for the 997 and 996 are limited to some extent. Why not find a set of used 18's in a stock width and go with an R compund tire. I agree that better tires do hide some sins of the 911 but so does all the upgrades of the last 50 years to suspension, etc. Tires are good for 2 seconds a run going to the R compound. They should last you a season and save your street tires for the street.