That's a good suggestion on the Kosei. Hell of a deal for such a light wheel.

 

Keep it light and go with 15's......the less rotational mass the better. Not to mention the chassis was just not designed for anything bigger than a 16" wheel.....you will also benefit from greater ride comfort with a 55 profile tire or even a 50 on a 15" and not sacrifice much grip depending on the style of tire you get......with the money you save on a 15" you can get a better tire....I recomend the Konig Heliums.

 

Wanted to mention-

Just for fun I also did a test fitment of-
15x8 rims +36mm offset with 225/50-15 tires and that worked too, front and back no rubbing. It's taller than stock as well and very wide but OK.
205/50-15 and 225/45-15 would also work.

The rims are 949racing.com 6UL that usually fit Miatas and MINIs.
Comes in 15x7, 15x7.5 and 15x8 that would work for the Fit.

15x8 weighs about 13 lbs each.

Probably 205/50-15 would give the lightest wheel tire combo while
225/45-15 the best fit for a 15" wheel up to 8" wide and more contact patch.

Also did a fitment for-
17x7 rim +42mm offset
205/45-17 worked OK no rubbing
205/40-17 would be better, 215/40-17 probably would work as well.

 

That looks like a good option too, and a pretty good deal for a light wheel. But how is it that the two wider sizes weigh LESS than the 15x7 size?

949Racing

Also, I'm a little surprised that you got NO RUBBING in a 15x8 +36 wheel on the Fit. How about at full suspension compression? My 16x7 +40 offset wheels with 195/45 tires rub the fender lip over bumps, especially with any weight in the back of the car.

 

Wheel weights have to do with the offset of the wheel, they are close but the 15x7 with +25mm offset is the heaviest.

I did not load down the car with passengers but I did look from under and behind and it did look OK. Normally I do performance driving with only one person in the car so I think it will be OK, certainly the rim itself was clear so choice of tires would be a consideration.

In the rear there is relatively less room next to the shock but it's good with the +36 offset and 15x8 sized rim.

I didn't try going over any big bumps just normal streets and some turns, it did fine.

 

where did you find such light wheels... i want some 15"s for my car that are light what would you guys say for my gf210 springs?

 

Got my Enkei RPF-1s (~9lbs each) from Dynamic Auto Sports in California. 15" +41mm offset, and I am dropped with Tein S-tech springs.

 

I think any time you're dealing with really limited power, lighter wheels/tires are going to make a bigger difference. Not just in acceleration & braking, but in bump/dip handling as well. If the weenie shocks aren't up to controlling the relatively heavy OEM wheels, it'll get worse with heavier parts. I noticed this when I tested 225/50's on my lighter Saturn wheels. That combo weighed 3# more than my OEM wheels/tires, and you could really feel the difference over even small bumps.
Running lighter wheels/tires is also like adding free HP the same way changing to a lighter flywheel does, only without the sacrifice in drivability. It's a win-win.

HF

 

What is considered lite for 16"?

 

I would say anything that weighs in at or below the weight of the stock setup. The stock wheel/tire weighs about 35#. You can check tire weights on tirerack.com for various tires you're interested in. Edgeracing.com has some tire/wheel weights as well. Using that info, the stock wheels are about 17# ea, and the stock tires are about 18# ea.

HF

 

Any rubbing at all?

 

I've got 16x7 wheels that weight about the same as the OEM Fit Sport wheels. But the 16" tires weigh significantly more which made the overall combo about 4# heavier than stock.

Hey HEMI: How did you like the handling with 225s on those Saturn wheels -- aside from the weight? Any rubbing?

 

Yes, +41mm offset rubs. I did a few little adjustments here and there and now I no longer rub, even on hard corners. It was only rubbing in the front. The Tein drop is quite aggressive.. if you go with other springs, Skunk2, Eibach, Tanabe GFs you'll be fine.

My rim and tire combo weighs 26.5lbs per corner (General Exclaim UHP 195/55VR15). My stock 15" rims w/Nexen winter tires weigh 40lbs per corner. I notice a HUGE difference when i switch back to my summer wheels.. gas mileage, handling and acceleration.

 

I took some photos of the setup, but haven't uploaded them to my website yet. Here's the general scoop...

I tried two types of tires, because I didn't have a whole set of 4 that were nice enough to test with... these were my left-over autoX and street tires from my old Daytona. Fronts were an off-brand tire that was pretty wide in the tread. The rears were some old Sumitomo HTR 50H's that were narrower through the tread. The front is more tolerant of wider tires than the rear, in my experience, so that's why I set it up the way I did.

With +50mm offset, the 225's in front would rub OCCASIONALLY on REALLY hard bumps, but I could never find where exactly. The rears with the narrower tires would also only rub occasionally, but a little more often than the fronts. However, I COULD see where it was rubbing. There is a small tab on the INSIDE of the wheel well, towards the back end of the car. This little tab showed some "polish" marks, so on a hard compression, it would rub. There are also some rub marks on the plastic shock dust cover.

I'll post those photos in one of the "shoes" threads, along with the dimensions of the tires I used - can't find that data at the moment. The result of my little experiment is that if you have to find a narrow 225, it's hardly worth the effort and weight just to say you've got 225's on the car. Sure, they look nice, but I can find 205's that have nearly as much rubber on the ground as a narrow 225 without the weight penalty.

HF

 

Thx for the reply. That was sorta what I figured about 225s as well, but maybe some rigorous testing with same-brand tires would reveal more.

That tab on the rear fender is a real design flaw by Honda, IMO. It rubbed bad with my 16x7 street tire setup going over bumps with my 2 dogs (140 lbs.) in the back. I was able to use a file to shave the sharp corner off the tab substantially and that helped.

 

The tab I'm talking about is on the INSIDE of the rear wheel well... the part towards the center of the car. I was sure I was going to have trouble with the Evil Bolt on the outside of the wheel well - the one that the bumper cover attaches to - but that wasn't the case in this instance. Strange, but that's what I found.

FWIW, here are the measurements I got from my tires:

Front - "Sport Radial GT", a GY Gatorback knock-off
Section width = 8.75"
Tread width = 8.0"+

Rear - Sumitomo HTR 50H
Section width = 8.5"
Tread width = 7.5"

So, whatever you do, it appears that about the maximum width for a 50mm offset 6" wheel is about 8.5", and that still has a little bit of rubbing on the shock and the little tabby thing. For my money on a street-type tire in 205/50, the Sumitomo HTR-Z has a 8.2" section, a 7.8" tread, and is only about $50 @ Tirerack. A Kumho MX has an 8.5" section (no tread listed, but they're WIDE size for size), and is $70-something.

HF

 

You should know that its not only the weight of the wheels but also the weight of the tires and the radius of the weights.

When you put 205/50x15" tires with a diameter of 23.44" the weight of the tire is 21#. The wheel weight is 12.6 pounds. So the rotational deadweight is 12.6# at 5.5" and 21# at 11.7". The torque to rotate the wheel is 5.8 lbft + 20.5 lbft. The total torque resistance to turning is 26.3 lbft. However the main resistance is the tire at 20.5 lbft.

So lets put 17" wheels and 205/40x17 (23.44" diameter) tires on. The 17" wheel weighs 14 lb at 6.5" and the 17" tire weighs 19 lb at 11.7". That torque resistance is 7.6 + 18.5 lbft or 26.1 lbft.
Again the main resistance is the tire at 18.5 lbft.

In this case the 17" combo has less torque resistance than the 15" and therefore should accelerate faster with whatever torque the engine can develop. The less weight at the outside the easier you will accelerate the rotational speed.

Thanks to TireRack for tire specs and Grassroots Motorsports for wheel data (their ads list the wheel weights) - which vary all over the place so my little example isn't true for all combo tires/wheels. Generally it is because the tire weights are at the fartherest radius and that makes them controlling, generally.
This is not a real precise calculation as I really should calculate the centers of rotating mass to get a more accurate torque. However, past experience has shown that indeed the tire tread is pretty much the controlling factor. The beefier the tire the more weight and slower accelerating. And thats why usually when going to wider tires you try to reduce the outside diameter a wee bit to reduce the torque resistance. A wee bit, not a lot.
See, thats why you went to Physics and Math classes. My students had to solve equations like this. And why dished corners were faster than flat ones.
cheers.

PS its also why you want to remove all wheel weights BEFORE mounting new tires and balancing.
Leaving the on just adds to weight being turned.

 

A little late to the party, but here's some more info to the original question

Effects of Wheel Size/Weight on Performance | Build A Faster Car

 

The weight of the wheels matter of course as it takes more power to accelerate the added 2.2 lb per wheel. 18 lb minus 15.8 lb is 2.2 lb.
However, thats only half the story.
Because the tire weight is further from the axle their centrifigal force is much greater than that of the wheel. If you save 2 lb on the weight of the tire you will end up with the same total weight but with the center of gravity now closer to the axle. And that means your Fit will accelerate faster. CF=mvv/r.
To 'solve' your question compare the addition of centrifugal forces of both tires and wheels.
If you subtract 5 lb per wheel and add 4.2 lb per tire and use 7" for the radius of the wheel and 11" for the tire radius what happens?
Its like stopping a spinning big tire vs a small light tire the same diameter.
And thats why as you increase tire width you should slightly decrease tire diameter. The less weight further from the axle the easier it is to spin the tire faster. To make up for more weight & rolling friction

 

u can't go wrong with lighter 15" (try enkei RPF1)