991.1 vs 991.2 wheel offsets
Thread Starter
Advanced
Joined: Jun 2016
Posts: 80
Likes: 3
991.1 vs 991.2 wheel offsets
I know the 991.2 has a wider rear wheel (i.e. 11.5 vs 11) but the offset is higher so there really is no change, assuming the chassis is the same.
Front is the same with a 2mm difference in offset so the rim is evenly distributed to the inside and outside of the mounting hub by 1mm in each direction. That's negligible.
Rear wheel is 1/2" wider with a 6mm greater offset. This means the amount of wheel to the inside of the mounting hub increased by 12mm and remained unchanged to the outside. In essence, there is more contact patch on the inside part of the hub.
The question is whether the track has changed or if it remained the same. The reason I'm asking is to determine whether I can use a 991.1 fitment to build aftermarket wheels or if I'd have to measure the new car.
Any thoughts on this?
Front is the same with a 2mm difference in offset so the rim is evenly distributed to the inside and outside of the mounting hub by 1mm in each direction. That's negligible.
Rear wheel is 1/2" wider with a 6mm greater offset. This means the amount of wheel to the inside of the mounting hub increased by 12mm and remained unchanged to the outside. In essence, there is more contact patch on the inside part of the hub.
The question is whether the track has changed or if it remained the same. The reason I'm asking is to determine whether I can use a 991.1 fitment to build aftermarket wheels or if I'd have to measure the new car.
Any thoughts on this?
Rennlist Member
Joined: Feb 2007
Posts: 5,009
Likes: 1,476
From: ^ The Bay Bridge
https://rennlist.com/forums/991/1106...-2-wheels.html
Rennlist Member
Joined: Feb 2007
Posts: 5,009
Likes: 1,476
From: ^ The Bay Bridge
From that other thread:
991.1 Carrera-line narrow body offsets for 20-inch wheels:
Front - 8.5 x 20 ET51 - 245/35 ZR 20 (91Y)
Rear - 11 x 20 ET70 - 295/30 ZR 20 (101Y) XL
991.2 Carrera-line narrow-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 49 - 245/35 ZR 20
Rear - 11.5 x 20 ET 76 - 305/30 ZR 20 (note: offset "only" changed 6mm, but wheel is further out in fender, as if on a spacer, also)
991.1 Carrera-line wide-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 51 - 245/35 ZR 20
Rear - 11 x 20 ET 52 - 305/30 ZR 20
991.2 Carrera-line wide-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 49 - 245/35 ZR 20
Rear - 11.5 x 20 ET 56 - 305/30 ZR 20
^ Above is best of my knowledge, and I encourage others to check the info; PCNA's configurator lists a number of 991.2 S/4S/GTS offsets incorrectly, which doesn't help matters. Please also note that there is an "XXL" extra wide body for the 991, used for the 911 Turbo/S and GT3/GT2 RS—but those live in their own forums.
991.1 Carrera-line narrow body offsets for 20-inch wheels:
Front - 8.5 x 20 ET51 - 245/35 ZR 20 (91Y)
Rear - 11 x 20 ET70 - 295/30 ZR 20 (101Y) XL
991.2 Carrera-line narrow-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 49 - 245/35 ZR 20
Rear - 11.5 x 20 ET 76 - 305/30 ZR 20 (note: offset "only" changed 6mm, but wheel is further out in fender, as if on a spacer, also)
991.1 Carrera-line wide-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 51 - 245/35 ZR 20
Rear - 11 x 20 ET 52 - 305/30 ZR 20
991.2 Carrera-line wide-body offsets for 20-inch wheels:
Front - 8.5 x 20 ET 49 - 245/35 ZR 20
Rear - 11.5 x 20 ET 56 - 305/30 ZR 20
^ Above is best of my knowledge, and I encourage others to check the info; PCNA's configurator lists a number of 991.2 S/4S/GTS offsets incorrectly, which doesn't help matters. Please also note that there is an "XXL" extra wide body for the 991, used for the 911 Turbo/S and GT3/GT2 RS—but those live in their own forums.
Trending Topics
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Rennlist Member
Joined: Oct 2018
Posts: 456
Likes: 120
A lot of people get this wrong, including Tire Rack and famous wheel makers...
https://rennlist.com/forums/991/1106...-2-wheels.html
https://rennlist.com/forums/991/1106...-2-wheels.html
I’m getting some wheels custom made and almost got the wrong offset because the manufacturer hadn’t done them for a 991.2 yet.
Rennlist Member
Joined: Oct 2018
Posts: 456
Likes: 120
My plans are for the opposite. I’m looking to fit some 315 or 325 and don’t care much for rims that are flush to the fenders. Just plenty of sidewall for maximum handling.
Rennlist Member
Joined: Feb 2007
Posts: 5,009
Likes: 1,476
From: ^ The Bay Bridge
Rennlist Member
Joined: Feb 2007
Posts: 5,009
Likes: 1,476
From: ^ The Bay Bridge
Thank you for sharing this—it shows just how special Guards Red (and a narrow-body 991) can look these days. Couldn't resist GR on my GT4, and sometimes wonder if I would have been happier with it on my 911. I have a real love/hate relationship with red cars...but certain cars look fantastic in red. Yours is one of them, and doesn't need a bunch of bodywork or other overt visual tweaks.
With springs and wheels, this 991 is right in line with the way Porsche designers dream about the cars and sketch them—and the way dialed-in 911s owned by enthusiasts have looked since the long-hood days. It's a personal preference, but it's why I prefer a 911 SC with the right wheels/tires and ride height to an as-delivered 930. It's also a lot of what sells all of us on RSs, GT3s, GT2s, etc.
Rennlist Member
Joined: Nov 2014
Posts: 476
Likes: 180
From: Media, PA
Thanks. My car is also lowered with Techart springs. I have a real love/ hate relationship with Guards Red. I love it until I see it next to my friends Carmine Red.
Also so thinking of changing the wheels up a bit. I really like the wheel design but cleaning is real pita and now I’m wishing they were a bit darker.
Also so thinking of changing the wheels up a bit. I really like the wheel design but cleaning is real pita and now I’m wishing they were a bit darker.