I wonder if the ratio is linked more to effort than true weight. I know that orthopedic docs will tell you that every extra pound on your gut equates to an exertion of 10 extra pounds for your back muscles. If I lose a pound of flab up front, I'm not 10 pounds lighter on the scale.:impatient My sense of this is that I can put 560 pounds of whatever in the Mini, seee how it rides, remove the stash and the perceived difference will be the gain perceived from spending $1200+++ on new tires and wheels

 

Its the acceleration and deceleration part that cutting unsprung weight = 20lb of sprung weight.

Also with a lighter wheel/tire, your spring/dampers will have to deal with less weight when its moving up/down, it helps a lot for traction on really bumpy surfaces or a sharp bump in the middle of a corner. This is the main difference between just cutting 500lb off sprung weight (weight supported by the suspension) and cutting 40lbs of unsprung weight (weight in the suspension components). You will not gain the same effect by losing weight up top as compared to losing weight down where things move.

If your roads are relatively smooth, you won't feel much difference.

There was a member here on NAM that timed his own car with a heavy set of 17" run flats, then a set of lightweight rim/tire, and yes, you do gain like 0.3s for 0-60 times if you change to a lighter tire combo.

 

Which might be useful if you had a drag racing car or for true road roadracing but, I assume, for normal road driving would not be noticeable (unless, of coursse, your flat out from every stop light)

 

How about any "significant" gas mileage improvement?

 

I've always heard that it's more like 10 pounds unsprung per pound sprung. I believe that. FYI, less weight in your wheels is orders of magnitude more effective than losing weight in the flywheel, because the weight in the wheels robs more torque than that of the flywheel. This is because of the greater radius of the wheel/tire than of the flywheel. The force necessary to spin something is higher as the radius goes up. [definition of torque]

 

Nope. less than 1 MPG.

 

First of all - it is NOT a linear rule - I would have though simple common sense (what the HELL happened to that anyway?) would have told any reasonable person that.

OK by THAT flawed logic, I dropped 440 lbs. from the car. I did not. It does not feel like it. It doesn't even feel like I dropped a light passenger. It doesn't even feel like the A/C shut off. It feels like less of an impact as simply putting on an intake - a SILENT intake. It is almost imperceiveable, at least ONLY dropping weight, staying with the same size.

The suspension may indeed be reacting faster. It is not noticeable on the street. The brakes may indeed be better at the extreme. It makes no difference on the street.

 

my 18" wheels are 16 pounds a peice and the tires are 20 pounds so 36 pounds total


a total of 19 pounds a side so 76 pounds total savigs!!

something i noticed alot more after swiching from the s- lights is i have alot more torq steer and the wheels are not as bullet proof !!!!!!:(

other than that it rocks and gas milage has risen quite a bit

the car just feels lighter on its feet witch is really nice

so also by that flawed weight ratio i just took out 1520 pounds out of my mini (hahahahahahahahaha)

i wish


anywho
later

 

This looks like where the weights in the FAQ came from ...



https://www.northamericanmotoring.co...ead.php?t=3500

Guess Goodyear runflats have been on a diet.

 

And this was what tirerack says on its site http://www.tirerack.com/tires/Spec.j...1=yes&place=17

22 pounds???

 

Obviously the weight of these tires has changed since Alex originally posted it and the MINI2 FAQ was written.

The MINI2 FAQ has links to the Tire Rack pages for each of the OEM tires they sell. Clicking the tire name in the FAQ and then SPECS on the Tire Rack page would have provided the "current" weight.

The "Contact FAQ Custodian" link at the bottom of each MINI2 FAQ can be used to report discrepancies.

 

All tire data is taken from Manufacture's specs

Alex

 

I did many months ago.

Screw the Mini2 FAQ. We should have our own on NAM.

 

Is it possible that the OEM tires are different from the ones offered on Tire Rack? That could account for the weight discrepancy.

Anyway, shedding 60-lb of unsprung, rotating mass IS noticeable.

 

It is when combined with dimentional changes - which is more noticeable that weight alone.

 

Anyone know what the weight here is?

 

No offense chows4us, but you are dead wrong with this. There is a HUGELY noticeable difference in lighter wheels and tires. I replaced my S-Lites and Dunlop Runflats a month with 15" SSR Comps and Toyo T1-S tires, shaving off something like 25 pounds per corner, and the difference is enormous, and I mean enormous. The car feels like the old car on steroids. It is *significantly* quicker, and far more agile. Of course that's due to the nicer tires as well.

But anyway, playing down wheel/tire replacement as if it doesn't affect much is just crazy-talk. It is an incredibly beneficial mod. And saying that a 0.3 second difference in 0-60 "would not be noticeable" is also ridiculous. That's a BIG change in performance, which illustrates exactly what I'm saying.

-mike

 

Well.. when my car does get here... I will just use up the run flats and it is time for new tires...I will get non-runflats...

 

No offense taken. I said:

"Which might be useful if you had a drag racing car or for true road roadracing but, I assume, for normal road driving would not be noticeable (unless, of coursse, your flat out from every stop light)"

Your telling me that in "normal driving" unless your WOT from all stops, you find it "useful"? Why do I find that hard to believe? Remember, I'm not saying its not nice to have. I said I found it difficult to believe it would be noticeable unless your WOT.

I used to have, at the same time, a SC MR2 and Turbo MR2 (stock). Factory claims 7.0 and 5.9. 1.1 secs is MUCH more than 0.3. BUT, in normal driving, there was no difference. Was the turbo quicker??? MUCH But, in normal driving I do not believe there was any difference because your not driving flat out all the time

IMHO. Maybe you feel a difference and thats GREAT

 

OK, I see your point that it may not be "useful" by some definition. It is in fact highly noticeable in everday, non-maniacal driving, though, and I can certainly feel the difference at all times. Your experience with MR2's is anecdotally interesting, but not really relevant, IMO. This is a different car, and 0-60 can feel a lot of different ways in different cars. But anyway, just wanted to point out my opinion that it is indeed a significant difference that is certainly not limited to crazy driving. You should really try shaving off 25+ pounds per corner and then see what you think, because it makes a big difference in the overall character of the car.

-mike

 

I have a set of R81 Holeys w/Conti's (about 28 lbs) and a set of R82 Silverstones w/Kumho's (about 35 lbs). That's about a 7 lb difference, and I can definitely feel it. 25 lbs a corner would be huge.

 

Changing to a much lighter wheel/tire combo is noticeable in every day driving, such as getting rolling from a stop. There is less mass to get moving (both spinning and going forward), so less throttle and/or clutch slip is required. It's not like the difference between a n/a and turbo MR2 where the powerband is wildly different. MINI sort of did us a favor by using such ridiculously heavy components that we can notice a change by switching to readily-available and inexpensive lighter ones. Thanks, MINI!

 

LOL, there ya go! Well chows, that's two who have actually changed their wheels and agree with me... It really does make a big difference.

-mike

 

OK, since you all have, I havent yet (way too new), you got the experience and not me

But, i dont see how to get 25pounds off per wheel. I got 24 pound wheels, 22 pound tires. 17". Even Comp SSRs are 13pounds, that saves 11. Tires save 1 pound. thats 14. So, unless going to 15", I dont see where your getting 25 pounds

 

Remember that the S-lite/Badyear combo weighs 50 lb. not 46 lb. You're right, 25 lb. is a lot to lose. But, losing half that is easy and inexpensive ... and you still end up shedding 50 lb total of unsprung, rotating weight.