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#1 2005-07-11 16:18:57

joefrompa
Member
Registered: 2005-06-14
User Number: 214
Posts: 289

Weight of stock 16" wheels

Hey all,

Can someone, anyone, give an accurate weight to the stock 16" wheels...or even a very good estimate?

I'm looking at wheels in the 17" range from 14-16 pounds and want to ensure that I'll be dropping weight, not adding it. My goal is a 3 pound drop at each corner including tires. (4 pounds would be even better, obviously, but I'll stick to a goal of 3 right now)

Thanks for anyone's help!

-Joe


9-2x Arctic Silver Aero 5-spd. 20% tint all around. 7000+ miles...20mm Rear Sway Bar sitting in a garage waiting for time to install

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#2 2005-07-11 16:35:28

Snaab9-2
Your Arms Off
From: Delaware
Registered: 2005-06-20
User Number: 283
Posts: 4211

Re: Weight of stock 16" wheels

Joe... I can't remember why I read it but someone posted 16.5 pounds for the OEM 16 inchers.

Don't over look tire weight.  When I was shopping for tires on the Jetta, they would vary by up to 4-5 lbs!


05 Red SAAB 9-2 Aero 5 Speed: AP Stage 2 93 - FHI 20mm Rear Sway Bar - Stromung Shorty DP - STI UP - STI Axle Back

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#3 2005-07-11 16:59:28

joefrompa
Member
Registered: 2005-06-14
User Number: 214
Posts: 289

Re: Weight of stock 16" wheels

yeah, that's why I said tire included....

16.5 pounds....that means if I could get a 14.5 pound wheel and a 1 pound less tire....which is nearly impossible when upsizing to a 225-45-17 or 215-45-17....

hmm, it's gonna be tough smile

thanks!


9-2x Arctic Silver Aero 5-spd. 20% tint all around. 7000+ miles...20mm Rear Sway Bar sitting in a garage waiting for time to install

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#4 2005-07-11 17:05:57

joefrompa
Member
Registered: 2005-06-14
User Number: 214
Posts: 289

Re: Weight of stock 16" wheels

oh yeah, just fyi, the stock tires according to tirerack are 21 pounds a piece.

Supposedly a good rule of thumb is that for every pound removed from the wheels/tires/unsprung weight, it is the equivalent of removing 3 pounds of regular weight

So my goal of 100 pounds weight removal could be greatly aided by removing 4 pounds per tire (apparently going from ~38 pounds per hub to 34 pounds) would be an approximate decrease in accelerating mass of about 48 pounds....plus spare tire, tools and jack, headrest, and a lightweight battery...and we should be over 100 pounds.

and that should equate to about 8 wheel HP

I hope smile


9-2x Arctic Silver Aero 5-spd. 20% tint all around. 7000+ miles...20mm Rear Sway Bar sitting in a garage waiting for time to install

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#5 2005-07-12 00:20:57

T-St Saab
Member
Registered: 2005-05-31
User Number: 122
Posts: 33

Re: Weight of stock 16" wheels

i too subscribe to the idea of decreasing rotational mass . . . i've spent a lot of time riding bikes and it really shows there.  however, i've seen all sorts of ideas as to what the ratio of wheel weight removed vs. regular weight.  does anyone know for sure . . . joefrompa says above that it is a multiple of 3 . . . i've also heard a multiple of 1.8 . . . does anyone know for sure?

also, don't forget the importance of good tires . . . this can more than make up for a few extra pounds.

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#6 2005-07-12 10:48:41

joefrompa
Member
Registered: 2005-06-14
User Number: 214
Posts: 289

Re: Weight of stock 16" wheels

I will say a couple of things on that supposed ratio. It's totally hearsay as far as I know.

If I buy a 20 pound wheel but 60% of the weight is in the hub, and I buy a 16 pound wheel but 60% of the weight is in the outer rimi, I fully expect to be slowed down by the 16 pound wheel as it acts like a heavy ass gear on the car when accelerating.

Same thing with tire. I believe a 2 pound lighter tire will significantly lower the overall force required compared to a 2 pound lighter wheel.

Weight distribution is probably more important that the actual weight on a scale. And I'm no engineer or physics major, so I don't know the formulas etc.

I believe that from a standing start, relieving wheel/tire/flywheel/engine/driveshaft weight will result in a significantly faster acceleration than just relieving "dead" weight from the car (such as a spare tire).

Everything that rotates in your car contributes to the acceleration, as it all acts as a "gear" on the car. That's why lightened flywheels and camshafts made out of lighter alloys can make a car feel so much faster than it's hp/tq numbers suggest.

But I digress....


9-2x Arctic Silver Aero 5-spd. 20% tint all around. 7000+ miles...20mm Rear Sway Bar sitting in a garage waiting for time to install

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#7 2005-07-12 12:31:56

john_matrix
Administrator
SupporterModerator
From: Asheville, NC
Registered: 2005-06-06
User Number: 168
Posts: 23458

Re: Weight of stock 16" wheels

joefrompa wrote:

I will say a couple of things on that supposed ratio. It's totally hearsay as far as I know.

If I buy a 20 pound wheel but 60% of the weight is in the hub, and I buy a 16 pound wheel but 60% of the weight is in the outer rimi, I fully expect to be slowed down by the 16 pound wheel as it acts like a heavy ass gear on the car when accelerating.

Same thing with tire. I believe a 2 pound lighter tire will significantly lower the overall force required compared to a 2 pound lighter wheel.

Weight distribution is probably more important that the actual weight on a scale. And I'm no engineer or physics major, so I don't know the formulas etc.

I believe that from a standing start, relieving wheel/tire/flywheel/engine/driveshaft weight will result in a significantly faster acceleration than just relieving "dead" weight from the car (such as a spare tire).

Everything that rotates in your car contributes to the acceleration, as it all acts as a "gear" on the car. That's why lightened flywheels and camshafts made out of lighter alloys can make a car feel so much faster than it's hp/tq numbers suggest.

But I digress....

yeah what he said.embeer

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#8 2005-07-18 12:54:15

roamin'coyote
Member
From: Chester County, PA
Registered: 2005-07-05
User Number: 449
Posts: 172

Re: Weight of stock 16" wheels

[offtopic]what part of PA joe[/offtopic]

On my wrx wagon, I had heavyish 17s (OZ/Prodrive P1s ~19lbs) and the difference in performance was easily noticeable.  Not only on acceleration, but the action of the suspension (unsprung weight).  So, I downsized to 16"ers lighter weight, cheaper tires.  If you get a 16x7 wheel, size 225/50-16 fits very well and doesn't mess with the speedometer much/if at all.  225s are a little bulging for a 6.5" wheel.  Be sure to watch offsets and tire widths (a lot of variation) as you may get rubbing in the rear.

-wYlie

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#9 2005-07-18 13:12:51

joefrompa
Member
Registered: 2005-06-14
User Number: 214
Posts: 289

Re: Weight of stock 16" wheels

Hey, I  looked at your wagon in the sig...but I couldn't quite tell a few things. Just want to confirm:

Were those the 16" wheels you were referring too with the 225/50 on them? Was that with your car lowered already, because the ride height looks good with a 225/50/16.

Did you feel the size of 225/50 was appropriate for the vehicle in the way of steering response, handling, etc.? Any mileage changes? How did lightweight 16" wheels and tires feel as far as acceleration?

Thanks!

-Joe


9-2x Arctic Silver Aero 5-spd. 20% tint all around. 7000+ miles...20mm Rear Sway Bar sitting in a garage waiting for time to install

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