anyone know the benifits of lightweight wheels?

[CaysE]

I can't tell if you're being sarcastic or not, so based solely on the fact that you haven't been sarcastic in this thread yet, I'll guess that you seem to think both of those cars in your theoretical race will make it to the finish line at the same time?

I can tell you right now, 80 lbs will make a huge difference in a Yaris, and the 120lb driver will make it to the end first.

[fu_im_from_texas]

Originally Posted by CaysE

I can't tell if you're being sarcastic or not, so based solely on the fact that you haven't been sarcastic in this thread yet, I'll guess that you seem to think both of those cars in your theoretical race will make it to the finish line at the same time?

I can tell you right now, 80 lbs will make a huge difference in a Yaris, and the 120lb driver will make it to the end first.

I agree the lighter car would be faster...not sure that it would be by a large margin though... 80/2300 = .03 or 3%...is 3% that much greater than my less than 1% calculation? ... pretty close...

check out http://www.060calculator.com/

for 106hp and 2300lbs = 9.09 seconds
for 106hp and 2380lbs = 9.33 seconds

1-(9.09/9.33) = .025 or 2.5%

Is it safe to say that lighter rims will increase accelleration by less than 3%? Is 3% a huge difference? or is 3% a small difference? I could make strong arguments either way ...

[Biggie™]

Originally Posted by fu_im_from_texas

Is 3% a huge difference?

Well, let's step back and look at this with a tad bit wider view. The Yaris isn't a dragster, nor is it an exceptional road racer. But when taking into account the fact it has a steering wheel and brakes, we'll head towards the road race/autoross (along with aggressive street driving) side of things when looking at the benefits of smaller wheels on a Yaris' over all performance.

Take that 3% improvement and factor it into not just acceleration, but braking and turning. In a 0-60 pull, you saved 0.22 of a second. Not really that much time. But that was when looking at less than 10 seconds of performance data.

Now go to an autocross. And for arguments sake we'll say the Yaris ran a 60 second lap. And to make it even more interesting we'll drop the performance gain of the wheels to only 1% do to the fact the car wont always be accelerating, decelerating or turning (even thou it will be doing two of these simultaneously for most of the event). That's only a performance gain of 6/10th of a second overall. But as anyone that has autocrossed knows, that is actually a HUGE amount of time when competing. Now go to a race track where lap times are a minute forty or more and you've just beat your previous time by over a second. Kind of scary when you start to think about it...

[fu_im_from_texas]

Originally Posted by Biggie™

Well, let's step back and look at this with a tad bit wider view...

of the 6000+ threads on yaris world 41 are under "Tracking, Racing, Auto-X Forum"


... the majoity of yaris owners will not notice a 1% increase in accelleration

[cleong]

Originally Posted by fu_im_from_texas

of the 6000+ threads on yaris world 41 are under "Tracking, Racing, Auto-X Forum"


... the majoity of yaris owners will not notice a 1% increase in accelleration

First you calculate that there is a small advantage to lighter wheels, then you call it insignificant because it is 0.000-something percent of gain. Then when proven otherwise, you change tack to say that the gain is irrelevant, since we are just discussing an econobox - a car that most Yaris owners don't drive competitively.

So have it your way, install your 17, 18, 19, even 20 inch wheels on your Yaris, it is your car anyway.

But you will see its effects in fuel consumption, and that doesn't fall under tracking, racing and autocross.

[fu_im_from_texas]

Originally Posted by cleong

...Then when proven otherwise, you change tack to say that the gain is irrelevant, ....

I claimed that lighter rims would have less than 1% improvement in accelleration. Then, you suggested a 1:4 ratio, which comes to about 3.47 % improvement. Please note that you did not "prove" anything... you simply suggested a different approach ... and I assumed it to be true...

Had I known we were going back and forth over 0% vs 3.5% I would have said "You are right" a long time ago...

[Biggie™]

Originally Posted by fu_im_from_texas

of the 6000+ threads on yaris world 41 are under "Tracking, Racing, Auto-X Forum"


... the majoity of yaris owners will not notice a 1% increase in accelleration

Well, there are close to 500 threads in the performance section, and most are looking for the ability to accelerate and or deceleration faster. That doesn't even take into account the hundreds of thread concerned with handling. Lighter wheels will improve maneuverability far more than a strut tower brace. So needless to say, the overall improvement lighter wheels give you would actually be interesting to more of this forums members than you first thought. I also used a 1% improvement in my example for the sake of argument. But again, a calculated rotational total reduction in weight of 80 pound from a 2300 pound Yaris is actually 3.47%. So go back and recalculate using that.

Now on to the real fun, I know this will go a little beyond light weight but smaller and lighter are even better... ;)

Using your reasoning, adding weight in the form of big heavy wheels and tires has a negligible effect. So with all the buckets of cash you get from your high paying engineering job, you go out and get some hot new 20 pound each 18X7.5s, for your luxury sport coupe Yaris. You also get yourself some nice 215/35-18s for that sweet low profile look that all the ladies like... Then there's me, with my job in the auto performance and motorsports industry. I go and find myself a set of 8.5 pound 13x7.5s along with some sweet lil' 215/50-13s.

One of my wheels and tires together runs just under 25 pounds each, while yours are coming in somewhere OVER 45 pounds. My tire is 21.46" tall, stock is 23.74"(we'll use this information later) and yours are 23.93" tall. Use this to determine the large amount of energy it will take you to turn your heavy wheel and tire when compared to my lighter and more compact wheel and tire unit. Don't forget most of your mass is almost an inch further out from center. And that's over 20 pounds per wheel and tire unit, using the simplified 4:1 ratio and multiplying it by 4 wheel and tire units we get 320 pounds! Do you still think the majority of Yaris owners will not notice a 7.2% advantage in acceleration, deceleration and changing direction?

Now, with your advanced engineering mathematics, go back up there and use the tire diameters(heights) I listed to determine my improved acceleration do to the lower gear ratio when compared to your slower than stock acceleration and higher gear ratio. And while we are dealing with tire diameters and such, determine the amount of additional energy the stock brakes will need to use to slow your taller and far heavier wheel/tire units when compared to my lil' guys.

But at the end of all this, the ladies love 18's... Luckily for me, I'm married so she'll just have to deal with my nimble little egg shaped ecno-box. And all those equations should keep you busy for awhile.

[gaffo]

Originally Posted by Biggie™

Well, there are close to 500 threads in the performance section, and most are looking for the ability to accelerate and or deceleration faster. That doesn't even take into account the hundreds of thread concerned with handling. Lighter wheels will improve maneuverability far more than a strut tower brace. So needless to say, the overall improvement lighter wheels give you would actually be interesting to more of this forums members than you first thought. I also used a 1% improvement in my example for the sake of argument. But again, a calculated rotational total reduction in weight of 80 pound from a 2300 pound Yaris is actually 3.47%. So go back and recalculate using that.

Now on to the real fun, I know this will go a little beyond light weight but smaller and lighter are even better... ;)

Using your reasoning, adding weight in the form of big heavy wheels and tires has a negligible effect. So with all the buckets of cash you get from your high paying engineering job, you go out and get some hot new 20 pound each 18X7.5s, for your luxury sport coupe Yaris. You also get yourself some nice 215/35-18s for that sweet low profile look that all the ladies like... Then there's me, with my job in the auto performance and motorsports industry. I go and find myself a set of 8.5 pound 13x7.5s along with some sweet lil' 215/50-13s.

One of my wheels and tires together runs just under 25 pounds each, while yours are coming in somewhere OVER 45 pounds. My tire is 21.46" tall, stock is 23.74"(we'll use this information later) and yours are 23.93" tall. Use this to determine the large amount of energy it will take you to turn your heavy wheel and tire when compared to my lighter and more compact wheel and tire unit. Don't forget most of your mass is almost an inch further out from center. And that's over 20 pounds per wheel and tire unit, using the simplified 4:1 ratio and multiplying it by 4 wheel and tire units we get 320 pounds! Do you still think the majority of Yaris owners will not notice a 7.2% advantage in acceleration, deceleration and changing direction?

Now, with your advanced engineering mathematics, go back up there and use the tire diameters(heights) I listed to determine my improved acceleration do to the lower gear ratio when compared to your slower than stock acceleration and higher gear ratio. And while we are dealing with tire diameters and such, determine the amount of additional energy the stock brakes will need to use to slow your taller and far heavier wheel/tire units when compared to my lil' guys.

But at the end of all this, the ladies love 18's... Luckily for me, I'm married so she'll just have to deal with my nimble little egg shaped ecno-box. And all those equations should keep you busy for awhile.

Single myself - but if the "Ladies" judge a man by his car:

1. screw em
2. I'm screwed if I'm driving a Yaris - even one with 24" wheels! ;-).

You sold me!!!!!!!!
I know TINY is more fun - period. my tiny 12" Fiesta tires and my 13" Tr7 tires were pure gokart heaven.

Question and recommendations need Sir!

1. that weight you gave 8-1/2 pounds - was that for steel or alluminum (I LOVE Smootie hubcap retro look so have no need for aluminum wheels).

2. any tire/wheel brand recommendations?

3. can we go even smaller on Yaris? 12" maybe?

..................

thank you for such an informative post sir!

[Biggie™]

Originally Posted by gaffo

1. that weight you gave 8-1/2 pounds - was that for steel or alluminum (I LOVE Smootie hubcap retro look so have no need for aluminum wheels).

2. any tire/wheel brand recommendations?

3. can we go even smaller on Yaris? 12" maybe?

1: Steel wheels are heavy, always run aluminum!

2.a: The tire I basically used in my lengthy example was the 215/50-13 Sumitomo HTR 200. There aren't too many good street tires left in a 13", but you can find some nice race tires(DOT and full slicks).

2.b: There are a number of good looking super light 13" wheels , just do some research and buy what you like and can afford. Here are a few examples. They all wont work for everyone, some have rather low offsets for the Yaris, but they are still usable. I'd recommend the Lenso VPD 13x7.5, 4x100 +25 8-10 pounds? There is also an 8 pound TE37 13X8, 4x100 +20, but those are pricey. Here's a list of even more possible choices.

3: You can't find any good tires in a 12", stay with 13's.


Now, I used a 13" wheel to over emphasize my example. We could easily use a 15" wheel and still get similar results, but with more wheel and tire choices. Lets use a better fitting example for our Yaris.

Enkei RPF1 15X7, 4X100 +41 weighs only 9.5 pounds each.
Toyo Proxes T1r 205/45-15 weighs only 17 pounds each.

Those wheels/tires are 26.5 pounds each and are only 22.2 inches tall, so we still get the low weight, lower gearing and the rotational mass is still closer to center than stock.

[CaysE]

Originally Posted by Biggie™

Well, there are close to 500 threads in the performance section, and most are looking for the ability to accelerate and or deceleration faster. That doesn't even take into account the hundreds of thread concerned with handling. Lighter wheels will improve maneuverability far more than a strut tower brace. So needless to say, the overall improvement lighter wheels give you would actually be interesting to more of this forums members than you first thought. I also used a 1% improvement in my example for the sake of argument. But again, a calculated rotational total reduction in weight of 80 pound from a 2300 pound Yaris is actually 3.47%. So go back and recalculate using that.

Now on to the real fun, I know this will go a little beyond light weight but smaller and lighter are even better... ;)

Using your reasoning, adding weight in the form of big heavy wheels and tires has a negligible effect. So with all the buckets of cash you get from your high paying engineering job, you go out and get some hot new 20 pound each 18X7.5s, for your luxury sport coupe Yaris. You also get yourself some nice 215/35-18s for that sweet low profile look that all the ladies like... Then there's me, with my job in the auto performance and motorsports industry. I go and find myself a set of 8.5 pound 13x7.5s along with some sweet lil' 215/50-13s.

One of my wheels and tires together runs just under 25 pounds each, while yours are coming in somewhere OVER 45 pounds. My tire is 21.46" tall, stock is 23.74"(we'll use this information later) and yours are 23.93" tall. Use this to determine the large amount of energy it will take you to turn your heavy wheel and tire when compared to my lighter and more compact wheel and tire unit. Don't forget most of your mass is almost an inch further out from center. And that's over 20 pounds per wheel and tire unit, using the simplified 4:1 ratio and multiplying it by 4 wheel and tire units we get 320 pounds! Do you still think the majority of Yaris owners will not notice a 7.2% advantage in acceleration, deceleration and changing direction?

Now, with your advanced engineering mathematics, go back up there and use the tire diameters(heights) I listed to determine my improved acceleration do to the lower gear ratio when compared to your slower than stock acceleration and higher gear ratio. And while we are dealing with tire diameters and such, determine the amount of additional energy the stock brakes will need to use to slow your taller and far heavier wheel/tire units when compared to my lil' guys.

But at the end of all this, the ladies love 18's... Luckily for me, I'm married so she'll just have to deal with my nimble little egg shaped ecno-box. And all those equations should keep you busy for awhile.

At the risk of sounding like an ass... OWNED!

I'm sorry, fu, I'm not usually a prick...

[fu_im_from_texas]

Originally Posted by Biggie™

... Yaris is actually 3.47%. So go back and recalculate using that....

You are correct. I rounded 3.47 down to 3%. Sorry for the confusion... my mistake.

Originally Posted by Biggie™

...
Using your reasoning, adding weight in the form of big heavy wheels and tires has a negligible effect. ...

I simplified the problem, by compairing 15 inch 16lb steelies vs 15 inch 10lb rims. You are very correct with your 17s vs 13s example ... your 17 vs 13, and my 15 vs 15 are apples and oranges...

Sorry for the confusion, I probably didnt make it clear that the > 1% figure only applied to 15s vs 15s.