Weight of wheels and DD's

[Mark42]

Been looking at various wheels and like the replica ZR1's because they look factory. Wheels are a matter of personal taste, and I don't care for all the fancy alternatives available.

Got to thinking about the weight of the wheel (and don't forget bigger tires) and how it would affect a street car, especially one that is a daily driver.

So I did some checking and found the following:

OEM 16" 5 spoke weighs 19.5 lbs.
235 55 16 tire weighs about 25 lbs.
OEM 17" SW6/ZR1 chrome rim weighs 20.5 lbs.
275 40 17 tire weighs about 30 lbs.
Replica ZR1 painted 17x9.5 rim weighs aprox 25 lbs. (as per manufacture phone call)

The lightest wheel tire combo is the OE 16" 5 spoke w/235 50 16 totaling aprox. 44.5 lbs per wheel/tire.

Upgrade to an OE SW6 17" rim and the wheel/tire combo weight jumps to aprox 50.5 lbs per wheel/tire.

Upgrade to an replica zr1 17" rim and the wheel/tire combo weight jumps to aprox 55 lbs per wheel/tire.

So the heaviest wheel/tire is about 10.5 lbs heavier than the lightest OE wheel/tire.

I have upgraded wheels/tires on almost every car I owned, and never noticed an impact to performance due to the added weight. I have noticed the increased weight just from changing/installing the old/new tires. Yep, most after market wheels are heavier, and fatter tires weigh more than skinny tires. Gee, who would have thought.....:mrgreen:

But now knowing that buying replica/aftermarket wheels and tires will add about 10 lbs per wheel/tire, it makes me wonder if there is an impact I might actually feel. Especially in light of changing the steel drive shaft to aluminum made a noticeable difference under very specific conditions. That was about a 10 lbs savings in rotating mass. Now heavier wheels/tires could add as much as 42 lbs to the rotating mass of the wheels.

Any one done a wheel/tire upgrade and notice a loss of performance or change in performance due to the extra weight?

How about shock/spring performance with the bigger weight hanging outboard?

[LTb1ow]

Yup, ask any guy who threw 315s on replica ZR1s how the acceleration and braking felt after running stockers. You can def feel a change.

[Mark42]

Yup, ask any guy who threw 315s on replica ZR1s how the acceleration and braking felt after running stockers. You can def feel a change.

Well, that is a bit extreme, but it is well worth asking.

So, as per LTSlow, who with 315's noticed a difference in handling after installing them?

[LTb1ow]

:lol:

kirkevil went from stockers to replicas and he mentioned he noticed a difference.

[sweetbmxrider]

i did. i bet salad shooters are the lightest oem wheels. you also have to look at the diameter of the wheel compared to the ds. the larger the rotating mass, the more of an effect. look at drag and road race wheel weights.

[B4C]

If your going to get zr-1's try to get an oem set the replicas don't seem to hold up as well. My chrome zr-1's look great and there 9 yrs old now I've seen replicas with the chrome peeling off and they weren't even half as old as the ones on my car.

[Mark42]

If your going to get zr-1's try to get an oem set the replicas don't seem to hold up as well. My chrome zr-1's look great and there 9 yrs old now I've seen replicas with the chrome peeling off and they weren't even half as old as the ones on my car.

I avoid chrome wheels on a DD just for practicality. Even the best chrome gets crappy when exposed to road salt, and curb rash is forever.


I'll do a search on kirkevil and see if I can find his thread discussing the weight issue.

BTW, when I went from 235 to 255's on my 96 Camaro, that was just a tire weight increase of about 4 lbs a tire, and I couldn't notice anything.

Thanks.

[jts98z28]

i noticed a big difference when i went from chrome 16's with 245 tires to draglites wit 275's, and as far as curb rash goes it doesnt just happen to chrome wheels

[KirkEvil]

I noticed a significant difference going from stock 16s to 17x9.5x11.5 ZR1 replicas. Feels sluggish from a dead stop trying to overcome the added inertia force, and same from a roll. Braking was only slightly worse. If I were to do it all again I would have gone with some factory vette rims.

I never actually weighed the rims, but the rear 17x11.5 w/315s have to be close to 50lbs each, and the front 17x9.5 w/275s feel like 35ish.

[Mark42]

i noticed a big difference when i went from chrome 16's with 245 tires to draglites wit 275's, and as far as curb rash goes it doesnt just happen to chrome wheels

Just out of curiosity, what do you think happens when chrome wheels rub a curb?

[Mark42]

According to OEWheelsllc.com, when I spoke to them on the phone they said the 17x9.5 and 17x11 weigh just about the same, 25 lbs each. I asked how that is possible when one is 1.5" wider, and he said thats just the way it is. Okey Doky....

Anyway, OEWheels sells the rims with sumitomo tires, and according to sumitomo literature (regardless of whether or not you like them) their tires weigh 30.8 lbs for the 275, and 33 lbs for the 315. So even the heaviest wheel tire combo is 58 lbs, vs 51.3 for the factory 17 setup. Thats 6.7 lbs more than factory for 315's.

Doesn't sound like a lot, does it? I wonder if OEwheels is giving accurate info....

If you say you felt a difference, I believe you.

And yeah, salad shooters are probably the lightest, but they are also the least desirable appearance wise. :mrgreen:

[sweetbmxrider]

i have had my hands on a number of different wheel sets and i can tell you they feel significantly heavier. i think its going to be more than 10lbs but can't say its a fact.

sumitomo's are garbage IMO. many better tires out there.

[Mike]

Just out of curiosity, what do you think happens when chrome wheels rub a curb?

he meant it doesnt JUST happen to chrome, as in it can happen to all wheels

[Mark42]

i have had my hands on a number of different wheel sets and i can tell you they feel significantly heavier. i think its going to be more than 10lbs but can't say its a fact.

sumitomo's are garbage IMO. many better tires out there.

I used sumitomos as a weight reference because they list them down to the tenth of a pound. Some manufacturers don't even list weights!

[LTb1ow]

i have had my hands on a number of different wheel sets and i can tell you they feel significantly heavier. i think its going to be more than 10lbs but can't say its a fact.

sumitomo's are garbage IMO. many better tires out there.

Yea, I was thinking the same thing, my OEM rims weigh next to nothing compared to aftermarket ZR1s.

[KirkEvil]

The 17x11 do weigh more than the 17x9.5, especially with tires. Theres definitely way more than a 10 lb difference between my stockers and my zr1 replicas.

[MyFirstZ]

i feel like my 17x11 or 10.5'sTTM's with the 315 are very light. I was pleasently suprised the first time i took em off.

[Mark42]

This weekend I'll weigh one of my oe 5 spoke 16" w/235 and post the weight.

Kirkevil, can you weigh one of your 17x11 w/tire? Just use a bathroom scale if you don't have anything more accurate. I would appreciate it.

Anyone else want to weigh a wheel/tire and post the weight, it would be a great way to start a tire/wheel weight database here.

[jts98z28]

he meant it doesnt JUST happen to chrome, as in it can happen to all wheels

:nod:

[LTb1ow]

Mark, I will get a rough weight for ya tmmr of a OEM ZR1 with MT ET street tire on it.

[edpontiac91]

Going to a lighter wheel, I did notice a nice difference in the ride when I took off my stock 5-Blade Formula wheels and put on the black 16" Trans Am Diamond Spoke wheels (which I have been told were the lightest wheels ever for the 3rd Gens) that they weighed 16 lbs each.

[KirkEvil]

I'll see if I can find a scale some where here but it may take a few days Haha

[BonzoHansen]

Just to show some #s on weight change, since #s are better than buttdynos (http://kalecoauto.com/index.php?main_page=product_info&products_id=41):

New Super Chevy has an article on a new SS they have been modifying. This month they dropped the wheels and brake size. They wanted 17s on it to use tires with more sidewall. As with most mods, there is more than 1 change happening so it is not exact apple for apples. Here is a summary.

Front:
Removed
OE cast front wheels: 20x8, 245/45/20 PZero - 64 lbs each!
OE front 14" brakes
Added
4th gen front brakes
New 17x4 Bogarts with 4.5/26-17 tires:
front wt savings - 100 lbs
(the skinny tire alone should help some with less resistance)

Rear
Removed:
OE cast rear wheels: 20x9, 275/40/20 PZero - 68 lbs each!
OE SS 2010 SS rear brakes
Added:
2010 V6 rear brakes
17x9 SLP 4th gen 5-spokes and 274-40-17 hoosier d/rs - 34 lbs each
rear wt savings - 82 lbs

Total wt savings - 182 lbs - all unsprung

Running at atco they dropped:
60' time by .06 (1.86-1.8)
1/4 ET by .19 (11.81-11.62)
MPH up by 2.06 (199.27-121.33)
(last test used nitto 274/40/20 d/rs, so the trap gain was not all tire)

Those OE sizes are ridiculous. But I digress.

It appears no one makes 'skinny' 18s to clear the OE 14" rotors, thus the reason they killed the braking on this boat. De-braking is not for me! Especially in a 4000 pound car driven on the street.

I think the technical term is MOI - moment of inertia. Can any of you engineering students maybe expand on this? My humble knowledge is it takes more energy to get a heavier wheel moving and more energy to stop a heavier wheel. So there is zero question lighter is better.

So the practical question is saving a few lbs on a street only car really worth it? Probably not. Unless you are shedding a big pile of weight. Is it worth it on a car that is regularly raced - drag or auto-x? Sure.

[LTb1ow]

Not to disrail Mark's thread, but at basic, its like a engine flywheel. If you can get it going, it makes the engines job less and allows it to tackle load shocks easier as well, however it does take a lot to stop it... a heavier object requires more force/power to get it moving/rotating.

For wheels/tires, a lighter combo would be much better for stop and go because your engine does not have to work hard to get them moving, but if you were strictly highway driving there may be a slight benefit to having a heavier wheel as it will naturally want to keep rotating, so you may coast more etc.

[Mark42]

yep, I agree that heavier is worse. Especially when its an unsprung rotating piece. But even GM was able to put aside a nominal weight increase (even in light of the potential law suits from any unsafe/increased braking distance) in order to get fatter tires on the car. AKA 16" vs 17" factory rims.

Keep in mind there were no changes to the brakes when wheel and tire weight increased.

[Slow-V6]

When I had my V6 with my Heads and cam motor I made 225rwhp and 225rwtq. I wanted to put a 12 bolt in my car because I got sick of breaking the 10 bolts but aside from the cost of the 12 bolt I didnt want to loose power. There is a bigger drivetrain loss with the 12 bolt over the 10 bolt. On a LS1 car its not bad because the car makes 320 rwhp stock and loosing 5 hp isnt a big deal but on a car that makes 225 rwhp I felt I needed ever HP I can get.

I wanted to keep my car at stock weight. I did not want to start weight reduction because I drove my car to much. If you are worried about rotating mass and adding more weight then dont get new wheels! Of course there is another option for aftermarket rims. I had the Prostars skinny fats on my car. My front skinnies with 165 15 tires on them weighed about 22lbs and the rears with 265 50 15's weighed about 35 lbs. I had Futura tires from pepboys. My stock 16 inch chrome wheels with the 255 50 16 tires on them weighed around 48 lbs each. when it was all said and done my car lost about 80 lbs over stock with the new wheels and Aluminum D/S. If I had to do it over again I would have gotten the 16 inch Pro stars or the 15 inch Drag lights so I wouldnt have to grind the brakes down.

I did go from my stock 17 inch WS6 wheels on my 02 WS6 with Y2k 17/18 inch wheels. They are heavier and I did notice a little difference in acceleration with them.

[bandit88]

I think the technical term is MOI - moment of inertia. Can any of you engineering students maybe expand on this? My humble knowledge is it takes more energy to get a heavier wheel moving and more energy to stop a heavier wheel. So there is zero question lighter is better.


you pretty much covered that one..... minus the mathematical formulas
Its a simple concept.

if you really want more.... you have to wait till my real work is done ;)

[BonzoHansen]

I enjoy learning about this stuff. Matt's post equating it to a flywheel and such jives with what I've learned too. The heavier flywheel stores more energy or 'keeps the revs up' between shifts. So depending on intended use and application (car wt, gearing, engine setup, etc.) a lighter flywheel could be a gain or a problem. But I digress, we are not talking flywheels.

[WildBillyT]

I enjoy learning about this stuff. Matt's post equating it to a flywheel and such jives with what I've learned too. The heavier flywheel stores more energy or 'keeps the revs up' between shifts. So depending on intended use and application (car wt, gearing, engine setup, etc.) a lighter flywheel could be a gain or a problem. But I digress, we are not talking flywheels.

Not directly but it is the same deal in terms of physics. Doesn't matter if the weight is all metal or metal and rubber.

Having a lighter than stock flywheel is good to rev fast but bad for launching. A heavier than stock flywheel is good for launching due to stored kinetic energy but it's slower to rev up.

Applying that same thinking doesn't work for wheels (obviously). I don't see a benefit in using anything but the lightest wheel possible that meets your criteria (price, strength, tire choice).

To the OP:

I noticed a difference going from a 255/70/15 on a 15x7 steel wheel to a 275/50/15 on a 15x8 lightweight aluminum wheel. Yes, part of that can be attributed to the big aspect ratio change, but the wheel weight difference was 12 lbs PER WHEEL so it had to make a difference. Counting the tires, it was around 16.5lbs saved per corner in total.

Regarding handling, I haven't driven the car with the old wheels vs. new wheels enough to really notice. But from all I know and have heard, less unsprung weight will allow the wheel to better follow uneven road surfaces, leading to better handling.

[B4C]

Wolfblitz just went from stockers on his base v-6 to y2k vette rims...ask him about how the car feels now.

[creeper]

I've had:

stock ABS 16's with 245's
17x9 OEM zr1's with 275's
17x8/18x9.5 OEM y2k's with 245's/275's
17x9 OEM ws6 wheels with 255/285's

and the only difference i've ever felt is the difference in sidewall stiffness of the tires. 16's have felt mushy with both sets of tires i've had. zr1's with toyo t1s's were better. y2k's with kumho mx's were awesome. ws6's with kumho spt's are decent. no noticeable difference i can attribute to weight. the car follows ruts a bit more with wider tires but that's it. i suppose i did pick those wheels since they were lighter than something like a torque thrust. i'll take a slightly less blingy wheel to save some rotating mass/unsprung weight. i like the clean subtle look better anyway.

[JL8Jeff]

I can definitely say the OEM ZR1 5 spoke wheels are lighter than the aftermarket ones. My old 96 SS had the 5 spoke wheels and I bought a pair of 17x11 AFS ZR1 wheels and I found out one of my stock 17x9 wheels was aftermarket, not OEM. I had the tires dismounted and you could definitely feel the weight difference. 275/40/17 tires will handle a lot better than 245/50/16 tires so it's up to the individual if you want better handling for the added weight. But go with OEM wheels over the aftermarket if possible. OEM 17x11's are the wrong offset so you don't have much of an option if you want to go that wide.