Will I have problems?

[kimichi]

Will I have problems using 997TT stock wheels & tires - Mich Pilot Sport PS2 - Front 235/35-19,- Rear 305/30-19 on my 03 996 TT?

I've been reading about diff/viscous coupling problems using these sizes and some it's not a problem, plug and play. Some says no need for spacers and some do.

So, what is the verdict?

I don't track the car (no race track available), hardly ever get to use 6 gear (max speed limit 60), will never take long drives (around the island under 2 hours), and I drive it as a weekend car.

Edited December 10, 2013 by kimichi

[Loren]

You need to keep the overall tire diameter within 2% of original (per Porsche) - certainly no more than 5%.

[kimichi]

Loren thanks for the info.

I did some #'s and it seems the 19" tire size diameter is at the 2% of original 18" front and 5% of the rear.

Please correct me if I'm wrong.

F18-225/40/18=25.09"

R18-295/30/18=24.97"

F19-235/35/19=25.48"

R19-305/30/19=26.2"

F18-25.09+2%(0.5018)=25.59"

R18-24.97+5%(1.2485)=26.21"

I just bought the 997 TT wheels and those were tires it came with, it has 90% tread left.

Edited December 10, 2013 by kimichi

[Dus10R]

I guess if you're just posing around and want the look, no harm no foul. If you're concerned with handling, then stick with 18's. 996 wasn't designed for 19's nor their increase in weight & less tire deflection. You will have more tram-lining, your PSM will engage more often, etc. larger wheels are only useful if your running larger brakes, other than that they just look cool. And to find a 19 that weighs less than the 18 you are spending big big bucks.

[kimichi]

Yeah, I'm going more for looks and I'll be keeping my stock 18's too. So, will I need to buy spacers for any clearance issues? I've been reading 7mm for the front and 15mm for the rear with extended bolts or can I just plug and play? If I need those spacers will it be ok with the tires sizes? I don't have the 997 TT wheels yet so I can't try them on.

[wross996TT]

Hmmmm, been running 19" OZ rims with MPS2s 235/40 315/25 for 7 years now....none of the issues Dus10R claims...actually handles better than the stock rims I had.