Porsche's philosophy is to offer cars that are well balanced where the parts and pieces work in harmony. This philosophy seems to preclude offering sports cars that compete with cars offering far more horse power. Given this, what are the areas that we the consumer can control that ultimately effect a car's performance: weight. Weight is the biggest detriment to cars performing at their peak. About a year ago when I started to carefully consider the 991 CS as my next high performance car, I embarked on a research project about all things 911. Since at the time, the 991 offered a maximum of 430 factory produced hp, I knew that weight, or a lack thereof, would play an important role in how I optioned my car. This is what I found out. I hope this helps you as it did me. Please feel free to add to this; i.e.: weight of glass sunroof, etc..

“Our weight measurements have gotten some attention around Stuttgart, so I received this breakdown of options weight that goes some way (but not all the way) in explaining the difference between the claimed 1415 kg (3113 lbs.) and the 1530 kg (3366 lbs.) we measured with the first car we tested. These are figures communicated through the PR department:
PASM & PDCC: approx 24 kg, 52.8 lbs.
Sunroof: approx 15 kg, 33 lbs
18-way sport seats: approx 10 kg, 22lbs. (for the pair, delta vs the standard 4-way seats)
Sound packet BOSE: approx 4 kg, 8.8 lbs. over base
Sport-Design wheels: approx 4 kg, 8.8 lbs
Seat ventilation: approx 3 kg, 6.6 lbs.
Extinguisher: approx 3 kg, 6.6 lbs.
Another 4.5kg, 9.9 lbs. go in the fact that the DIN norm specifies a 90% tank while we measure with a full tank, so that's 6.4L of excess (unleaded) liquid at 0.7 density. They did not mention PSE so I am not sure whether any weight addition results from it, neither PCM.”
“PDCC components are:
an electronic control unit (in front of the car);
two valve blocks, one in front of the car and one in the rear;
one hydraulic pump with a hydraulic reservoir and one oil/water heat exchanger (all three in the rear of the car);
two special designed anti-roll bars (one front-axle bar and one rear-axle bar);
four actuators, two per each axle or one per each corner of the car (instead of connecting link/suspension/stabilizer on vehicles without PDCC)
Also pipes, liquid, joints, etc.
I estimate about 20kg. (44 lbs.) in parts and the heavier ones are in the rear.”

Weights of OEM wheels:
19” Base Wheel
8.5”x19” = 22lbs 11oz
11” x 19” = 27lbs 5oz

20” Carrera S Wheel
8.5” x 20” 23lbs 10oz
11” x 20 27lbs 12oz

20” Design Wheel
8.5"x20" 24lbs 11oz
11"x20" 30lbs 4oz

20” Classic Wheel
8.5"x20" 24lbs 3oz
11"x20" 28lbs 4oz

20” Sport Techno Wheel
9"x20" 27lbs 2oz
11.5"x20" 31lbs 1oz

Sound system weights:
Burmester 14 lbs. over base
Bose 11 lbs. over base

 

Thanks, lot of useful information. I would guess that full leather adds a few lbs too, but that's probably splitting hairs.

A couple of additional comments:
-when comparing the 991 to other cars, the same weight increase would apply between the base and loaded versions. It is true that between differently optioned 991's, the difference can be significant...
-PDCC adds weight but also allows higher cornering speed, so despite the weight increase, the impact may be positive on the car performance (not from a straight line acceleration standpoint of course).

In my case, I sometimes think I should have avoided the sunroof. But then, I open it when the weather is good, enjoy the PSE sound and forget about it.

As you pointed out, 18-way seats w/ventilation are incredibly heavy. Getting them out of my car when I swap them for the CF 997 bucket seats is ruining my back

 

I frankly never understood the fascination with weight on a street car. Even if you DE it there's no money for being first. If you are going to seriously race it you are going to strip out everything. I just get the options I want and I don't worry about it.

I will add that I do race and have two dedicated race cars so I don't track my street cars much anymore. When my 991 GT3 arrives I'll take it and give it a go but just to explore it's limits. I've had no interest in doing that with my 991S.

Just to be clear my race cars participate in LeMons and Chump Car so they are not expensive iron, but they are fast, light, reliable, and cheap... Can't wait for 2/2; first race of the season!

 

Agreed that one should probably ignore the weight of Porsche's options, but I do appreciate the fact that 911s weigh much less than competing sports cars. That was one of the deciding factors during my car shopping adventure.

I daily drive and track my cars. Lower weight equates to quicker responses, more control, and more enjoyment out of driving the car in general. Sure, for someone who doesn't care about racing or spirited driving, weight is a non-issue. But, I respect a car manufacturer who is able to offer such a perfect package in a perfect GT car, all while keeping weight down to 3,0XXlbs.

 

I agree and sometimes am a stickler when it comes to weight. I had gotten my last ZO6 down to 3K and it sure the heck made quite a difference in performance.

As far as my 991MS, I didn't worry all that much about the weight. I have a white car and I love the look of the black sunroof and wouldn't live without it. The car handles like a dream and still gets my blood flowing when I'm wringing it out on an open road.

If I were looking to compete with a Porsche, then I would have gone with a GT3, as the cost difference is negligible.

That being said, weight will matter with my next ZO6, which will replace my Terminator.

 

The added weight of PDCC makes me fell a little better about not getting it. I thought I had read somewhere the Burmester is actually a little lighter than Base, but I guess I made that up. Seats and sunroofs can certainly make a big difference.

 

"Porsche's philosophy is to offer cars that are well balanced where the parts and pieces work in harmony. This philosophy seems to preclude offering sports cars that compete with cars offering far more horse power."

I appreciate that lighter is better in general, but Porsche offers the Turbo or Turbo S for those wanting a lot more horses than the Carrera S, and suspension parts that provide performance advantages that outweigh suspension parts that weigh less on any track or street that has curves. Your Sport PASM probably lowers the center of gravity enough to improve handling more than deleting a sunroof.

 

Good point. Further, the second argument doesn't even make sense, to be honest.


1. The 991 CS *does* compete, and beat, multiple sports cars that have more power. That has never been a problem.


2. If you're still after more horsepower, you have the Turbo/Turbo S as an option.


There really is no argument that can be made. I'm surprised with the recent increase in threads like this.

 

good info! thanks. I guess if I was to order a Carrera S based on weight, it would be:
7-spd manual
no sunroof
no PDCC
manually operated seats to extent possible
rip out back seats
lightest wheels possible (20" CS rims apparently)
sound package plus? (just shoot me)
no sport chrono?
no PSE
carbon ceramic brakes


not sure how much I'd love this car compared to a fully loaded one but the case could be made!

 

OP - Great post. Thank you. Frankly I wish we had more of these on the board -- fresh info that is thought provoking if maybe not ultimately that useful in driving decision making.

Personally, I have all the options you list and wouldn't skip any because of the weight, but as a technical matter I find it interesting. T

Gasoline weighs about 6 lbs a gallon so if I really cared about shaving weight at the track I would run with no more than 1/4 tank at a time and save 72 lbs right there off a full tank.

I will say that when I have a passenger in the car, even my girlfriend who weights 120 lbs, the car is noticeably slower in accelerating.

 

Same here, and it is probably what triggered Bob to start this one trying to look at it from another angle than hp

I struggle a bit with all the buzz going on about "991's are underpowered", "991's are too expensive", etc. If people think it's too slow: don't buy it. Too expensive: don't buy it. Vote with your wallet, it's the only kind of vote that really works and were you vote is not overturned by a majority of idiots

 

I'm not saying that more horse power is better, because there is always a car out there that will have more power. What I'm saying is that at some point you have to look at weight in order to combat the idea that more power equals a better car.

Porsche has an entire line of 911s so the opportunity to purchase a car with the desired HP is there. If you look at the landscape you will note there is competition in the form of a Viper SRT, GTS and TA all of which have 640/600. You also have the Nissan GTR and the new C7 Z06. All of these compete quite nicely with the entire 911 line up, turbo s included.

My point is that more power is not necessarily better but that weight reduction is another way to solve the problem. And could it be that spasm in conjunction with no sunroof will improve handling even more?

 

You're comparing completely different cars, though. Most people who are in the market for a Viper will not cross-shop a 911S.


Further, look at the weight advantage the 991 already has: it weights less than 3,100lbs, give or take a few.


The GT-R? 3,829lbs.
The M6? 4,100lbs.


Weight is not a problem for the 911.

 

Good info...but sorry I'm ignoring it for now...too many threads like this lately...all I care about and luv is how it drives and extremely nimble for my taste..it has won best driver's car for a reason...cheers!

 

Easy for you to say- you got all the right stuff!