What offsets are ideal for 19x8.5/19.11.5?

2001 996tt. Lowered about an inch all the way around. Gonna go 235/35/19 + 315/25/19

 

Some reported dangers of running 315s. Potential for messing up the differential AWD. Search threads for that tire size. Also wheel calculator same site as offset calculator. Google it; it is helpful.

 

its actually the 305s you want to stay away from.. 315s are almost spot on for most 235/35 tires

 

I am learning from searching that there are differences between the 996 and 997 for tire diameter tolerances. Saw old post from Damon(tire rack) that 996 19" fitment should be close to 25.5 inch rolling diameter as possible front and rear. Is that correct 996 owners? Damon post from 3/07.

 

I think the ideal rear offset for 11.5 or 12" wheel is +37 and for the front +42. Does not rub with rear fenders rolled and sits fairly flush

 

That could be argued,

the 225/40/19 and 305/30/19 are closer in ratio then the 235/315 combo

 

...they are also too tall and will rub on a lowered car.

stock sizes are 225/40/18 and 295/30/18. usually when you upsize an inch you take 5 off the profile to keep overall diameter the same or close to stock.

 

...But too tall to be sure they won't rub. 235/315 is the best combo for correct OD overall, and for OD difference between front and rear. Saty within 4% front to rear and you should be OK. 996 is more forgiving than 997.

Stay about 51-55mm front on an 8.5", and 45-48ish mm on a 12" rear.

 

19x8.5+45
19x11.5+43

+37 is aggressive on a 11.5! I question the .5 increment on the rear wheel though? Why not step up to a 12" GT2 fitment or stick to an 11" ?

 

and to confuse things more, a 225/35/19 and 315/25/19 would be even closer and probably won't rub like a 225/40/19 and 305/30/19.

Oh and have fun finding tires for the 19" fitment. It is slim pickens to say the least and the ones currently available are expensive!

 

I realize that you have more experience then me, however I had 5 set of wheels on my 996tt in the last 2 years and offsets you listed will not look good at all especially 50s in the front will look terrible.

I respectfully disagree. 37 is not too aggressive it also doesn't rub. I currently have HRE 542Rs that are 47 front and 37 rear. Rear sits perfectly. Front needs a small spacer. My last set of Work wheels had 44 front and 38 rear. Here is how it looked . I will take a pic of new setup too....

 

^^Very nice! I am curious, why the 11.5 though? We usually go up straight to a GT2 fitment for the WB cars or stick to an 11". There is very little weight difference between an 11.5 and 12" barrel (1 piece or 3 piece).

 

That's why people are starting to run the 305/30 because the 315/25 is such a low demand tire, not many people are making it anymore. The 235/35 is readily available and will be for some time (oem fronts on 997tt)

Also with the 225/40 305/30 it does not rub at all at stock height, and with a set of pss10's the rear plastic fender wells needs to be pushed back a bit, and there is no issues, according to a friend with that setup.

 

I have 305's on hre 540 and they rub when lowered... Pirelli p-zero... Now it's time to get new tires...

 

I'm not surprised. That is a 26" wheel/tire combo. Too big for a 996TT.