Wheel weight?

2007 Cayman S 6SP. I am in the process of going after market for wheels. One set of wheels I am looking at weigh 26 LBS per wheel. Another weighs a bit over 20 LBS per wheel. For street use how much difference does the weight matter? Thanks all.

In power to weight terms "less is more" so the lighter wheels win in that purview. Having said that, I shed a few pounds per wheel with titanium screws. I like these fasteners, they are what Porsche should have used but it would be disingenuous to claim they made some kind of perceptible difference. My opinion would be buy the wheels you like the most and to reprise a post I made many months ago, if you need to drop some body weight do that instead. You improve your health and lighten the load.

It mostly depends on your definition of "street use." If you are like many of us here that enjoy spirited driving, you'll definitely feel the difference. Lightening the unsprung weight is one of the most effective ways to improve handling response, allowing shocks and springs to react more quickly. And going from 26 pounds to 20 pounds is a huge (~20%) difference.

IMHO, unless you are doing something which involves racing against a stopwatch you won't really notice the difference after a week. For street driving I'd go with whatever looks the best to you.

Good one about the driver losing weight. But I weigh the same as I did in high school. Many decades ago. So that is not an option. Funny u mention that though. Back in my motorcycle days people would spend crazy $$$ to take 5 lbs off the bike. Would have been far less costly to just lose 5 lbs.

As racergreg noted reducing unsprung weight is more advantageous than just a weight reduction. When I first got the Spyder Porsche was offering that 12 pound I think battery for 2,200. I'd wager good money nobody could feel that difference in driving. However, the accumulative effect of stripping the car interior naked and searching for every pound to reduce is defiantly a factor. More so in a boat, take a 27' cruiser and reduce the cookware, computers, TV extra coolers full of ice and you'll feel a HUGE difference.

I had a friend who installed some super heavy wheels on his ancient Corolla (I'm talking 70s era). They were smaller, but a lot heavier than the stock steelies. Granted, that car had squat for power, but it made the car barely accelerate. This is because of the increased rotational inertia - the weight is part of that, but the point is that the increased rotational inertia will make the car accel/decel much slower... I'd say that's another risk. Unfortunately, wheels don't usually list this value, but you can certainly say it's correlated to the weight. Bottom line, if you get a lot heavier, you will potentially feel it... but if the rotational inertia increases as well, then you'll feel that even more... In the end, reducing unsprung weight is very important to most... and is worth a lot more than just reducing overall weight. For this reason, I'd say be careful with heavier wheels...

Good points . I remember back in my motorcycle days when I went to lighter wheels. The difference was quite noticeable. That whole unsprung weight thing is real.

The rule of thumb is that a reduction of wheel weight is worth between 5 to 7 times a reduction in vehicle weight with respect to acceleration and braking. This effect is because of the rotational inertia of the wheels and the variability is a function of where along the radius of the wheel the weight in concentrated.

You must also take into account the wheel construction and quality. A wheel may weigh less simply because it is weaker and cheaply made. williamr

On my R53 Mini, I changed the 25 lb oem S-Lite wheels with 15.6 lb after market wheel Enkei PF-01 and immediately felt car to be more lively, lighter on its feet & better acceleration. The other benefit of lighter wheel is easier on the suspension components from wear and tear. Car being FWD and modded to 220 HP, the lighter wheel added more torque steer when I gun it but should be less concerning on RWD cars. Yes, I am for lighter wheel & tire.

We used to "borrow" from dead cars going to the crusher. I put Aluminum mags on my Fiat by such piracy in place of the steel wheels. They also used to offer cromodora magnesium wheels which were mad expensive and unfortunately brittle. Free aluminum wheels in HS and we had our own tire machine and balancer? Yes please. The 987.2 Spyder having the the lightweight 19" wheels without question is a key to my car's magic like performance.

Porsche ’s obviously have wider wheels than most cars… our front wheels are generally as wide as most cars rears… with that come weight.. if you want lighter and or wider come expensive… forged are even more.. if you can find a 19x10 or 11” under 20lbs for the street your doing just fine… if your tracking and want ALL the above there are only a few manufacturers that tick all those boxes… BBS, OZ , CCW, Fikse to name a few… these can hit the 5-10k range… it’s all budget.

I have two wheel sets that fit the race box. Both are forged, 18 inch, with a width of 9 in front and 10 inch rear. Titan 7 TS 5 with a weight of 17.1 lbs f and 19.5 lbs r while the Signature SV 104 are 18.1 lbs front and 19.8 lbs rear. The key here is the forged part. These wheels are made from a forged block of aluminum, when cut by a C&C machine to specific specifications. The Titan 7 were their standard with an offset of 46 f and 35 r, while the Signature were custom to 47 f and 35 r. The Signature wheels have a custom powder coated black chrome finish which adds a little weight.

On a daily-driver like mine, I'd be concerned about how sturdy the wheels are. Nothing like spending $2k on wheels only to bang one hard on a pothole and forever be a bit wobbly.

Ride quality and handling over bumps will be significantly inferior with +6 lb each wheel. Cornering difference is much more significant than acceleration delta.

That happened to me with an LM…. So good wheels bend too..

To bend a forged wheel takes a lot of force, most likely knocking the tire off the wheel. I would think you would have suspension breakage like happened to some GT4 front shock tower frame bed. What I find interesting is traveling over bumpy back country chip seal roads that were not rolled, OEM wheels with tires at lower than recommended PSI rates actually perform better because they have the ability to absorb the rapid movement due to their lower sidewall spring rate. I have noticed this with my OEM wheels with Michelin PS4S vs either Titian 7 TS 5 with RE71R's or Signature SV104 with Hoosier A7's. I have to change the Ohlin compression/rebound golden knob to 17 to 20 clicks from full stiff, otherwise my car just shakes all over the road with the light weight race wheels and stiff sidewall tires . The heavy duty Tarett GT sway bar do not help here as well as they do not soak up the bumps very well. I have these adjusted for turn in response and reduce weight transfer across the car, not to absorb the bumps side to side.

Suspension is the key for sure. I’ve always ran my coilovers on the lightest setting too.. the LM bent on my MR2. It was strange forsure.

I have 20” Carrera S on my 981 BS and love them. For the street they’re a little stiffer of course than an 18 or 19” wheel with more sidewall on the tires but I like the lower sidewall for steering precision and looks of course but I don’t really mind the ride. I’ve hit some really bad bumps unfortunately but have suffered no damage with the BBS - made for Porsche wheels. Just as an FYI, with new Michelin PS’4 tires the fronts weighed in at 24.5 lbs and the rears at 28.5 lbs. this seems pretty light to me and the car already has more performance than I can safely use on the street

If you look at it from a number standpoint, you can think of saving unsprung weight in a ~1:6 ratio. One pound of rotational mass saved is equal to saving 6 pounds of sprung mass. If money is no object and you're looking to track the car, then go for the lighter wheels. You're looking at 6 pounds of unsprung mass saved at every corner, so 24lbs overall. Multiply that by 6, you're saving around 144lbs of "sprung" mass. That being said, I don't think you'll feel the difference after a week or two of street driving it. If it's a street car that sees occasional spirited driving, then go for aesthetics.

You will feel a difference between light weight wheels and OEM sets with a stiff walled higher spring rate tire on a light weight wheel set on very bumpy back country chip seal road vs an OEM weight wheel with a much lower spring rate tire. That's assuming both tires weigh about the same. The heavy wheel set sort of glides over the road, while the light weight wheel set actually reacts violently, both from the less weight and the higher spring rate of the 35 side wall tires . However on regular surfaces, you will see the opposite effects. The lighter weight wheel set follow the surface much more closely keeping the tire tread traction much more engauged So, yes, saving weight on other parts of the car may work, but in reality who wants to strip out their car to save 144 vs just buying light weight wheels that are forged. You will end up with a lighter weight and stronger wheel. You may as well widen the wheel by lets just say 1 in f and 1 1/2 inch in the rear. This additional width will stabilize the side wall and also allow you to use a wider tire for more grip. The biggest drop in weight would be going from 20 inch wheels/ tires to forged wider 18 in wheels with a 35 side wall tire. More grip, less weight and better turn in. The reason I bring up this comparison is that the GT4 Club sport car comes standard with 18 inch wheels and tires due to this criteria. details from Apex wheels Many GT4 owners are inspired by the GT4 Clubsport and inquire about running an 18" wheel and tire configuration. 18" wheels will reduce rotational mass, decrease running tire costs, and open you up to racing slick compounds only offered in this diameter, however, the standard 6 piston 380mm steel brakes found on the road-going GT4 will not clear an 18" wheel barrel from any wheel manufacturer. To overcome this barrier, owners will purchase and install PFC brakes very similar to the brakes found on the Clubsport. The PFC BBK is quite an investment, therefore, many owners have opted to go with factory 997.2 GT3 /GT3RS 6 piston 380mm front brakes as a more cost effective solution. The good news is that our 18" EC-7RS & VS-5RS forged wheels offer massive brake clearance, and were engineered specifically to clear both the PFC Sport kit (pn 0.380.0001/2 Sport), as well as the factory 997.2 GT3 /GT3RS brakes. * They do not clear the PFC Race kit. Wheels Front: 18x9" ET46 // Rear: 18x10.5" ET44 Available in EC-7RS & VS-5RS Tires APEX Staff Pick: Front: 25/64-18 // Rear: 27/68-18 Factory GT4 Clubsport tire sizes A minimum of -3º of front camber is recommended Racing Slicks: Michelin Alternative 1: Front: 265-645-18 // Rear: 305-680-18 A minimum of -3º of front camber is recommended Racing Slicks: Pirelli DH Alternative 2 Front: 265/35-18 // Rear: 295/35-18 A minimum of -3º of front camber is recommended Extreme Performance Summer: Yokohama A052 (200 TW) R-compound: No options currently available Semi-Slick: No options currently available

Well after a lot of cruising the aftermarket wheel scene and sometimes getting even more confused by weight, diameter, width and mostly offset I found my solution. Found a beautiful set of 19" Lobster forks with almost new Bridgestone 's from a 2008 Cayman S . Found in the PCA marketplace. They have been completely refinished. Look perfect. Included are TPMS and new steel valve stems. My current stock wheels are 18". But a previous Cayman of mine had the 19" Lobster forks. I really liked them. So, this should be a plug and play swap I have been told. Very much looking forward to their arrival and getting them on my car. Thank you all for your input, insight and stories. Each and every one was helpful.

Lobsterclaws are a great choice, my personal favourite of all the OEM wheels. Ceramic coat the barrels and spokes before you install them if you can, it makes washing off the brake dust a lot easier!

So what are the weight of the 19" lobsterclaws with tires vs 18 OEM with tires ? Just checking.

I see different numbers out there on the interwebs, but I think conservatively 23lb for the 19x8 and 25lbs for the 19x9.5. Below are the weights of my sets - none of them are particularly light and some of these numbers are calculated/implied.