[Coastali8]

It doesn’t look like they fit very well. Appears the wheel and tire are outside of the fender. Or is that intentional?

[tommyb13662]

I can confirm 275/35r20 rear and 245/40r20 front on the stock rims fit 100% no rub. However the khumo ecsta ps91 max performance summer tires don't get a thumbs up from me. They grip so much more than the skinny stock tires. But they don't give confidence. The overlimit breakaway is not smooth or easy to control like the stock tires were. Possibly because they aren't fitted to the rim optimally.

[mws]

AG Luxury AGL 15s,
20X8.0 +40
20X9.0 +50

custom color-code matched for BMW Kristall White code C02, BMW Matte Blue (Frozen Blue) B94.

These wheels are both 1/2" larger than stock, but using stock Bridgestone S001s. In order to get a custom 1-piece forged 20" wheel in 8" wide, I had to have AG use a special narrow billet from HRE (and paid a good bit extra for it) in order to be able to maintain using the stock front 215 tires (so I did not add more weight/work to the electric motor in front). All the other forged wheel companies I looked at, did not have a 20x8" forged billet. Only 20x8.5". Sure, I could have done 3-piece, but did not want the possibility of added weight.

I wanted to save weight, or at least, not gain any weight. The wheels are generally about 3/4 lb lighter all around.









google photo album here, Normally I would not shoot in direct sunlight, but this color needs it. Otherwise the frozen blue stripes disappear.

https://photos.app.goo.gl/K4VHf43bswH499gR6

[Tazzie]

Absolutely stunning. I have never thought about wider wheels and tyres at the front would put more stress on the electric motor. Great point.

[mws]

Originally Posted by Tazzie

Absolutely stunning. I have never thought about wider wheels and tyres at the front would put more stress on the electric motor. Great point.

Thanks for the compliment! All the wheels on this thread look stunning.

As for the weight: my thinking: why challenge an already challenged 120hp electric put-put motor?

I had ordered a forged one-piece set from VS Forged for a Jag F-Type R I had last year. Those weighed a featherweight 20.2 lbs in front and 21.6 lbs in back. (btw: they are for sale, NIB: if you have an F-Type), and they were 20" like the i8, and even wider.

https://youtu.be/gXcTEEokUFs


I was looking forward to these 20" AG wheels (narrow than for the Jag I had made) weighing something similar, but sadly, they are in the range 24.5 lbs front or rear. The fronts weigh same as the back because the fronts have a huge, thick hub center without any drilled out pockets in back. "After" I ordered them, my wheel guy tells me if I wanted the pockets drilled out (to save maybe 1/2 lb) I would have to have paid $100 extra per wheel. (now he tells me?)

VS Forged just does all that weigh-savings drilling, by default. And for a base price of $2800 a set. (your eyes should be popping out of your head, right about now)

These AGs, with the custom HRE narrow billets for $125 extra, per front wheel, and $175 per wheel for the custom paint on all four, and made in the USA? $6800. They look great, but I am not super stoked about the performance goals I had.

The stock 625s are listed as "forged" by BMW

https://www.realoem.com/bmw/enUS/sho...diagId=36_2010

...and weigh front 24.32 lbs and 25.38 lbs rear. So I gained a wee bit in front. Lost almost nothing in back. Certainly did not save anything in front, after all that customization and spending of money... If I had done a 245 tire or wider wheels in front, I would have blown past my own personal objective.

Mr. FirstWorld™, I know.

[stressdoc]

The LCI 516 rims are light, at 7.9kg
But BBS RI-D are superlight https://bmwi.bimmerpost.com/forums/s....php?t=1327678

[mws]

Originally Posted by stressdoc

The LCI 516 rims are light, at 7.9kg
But BBS RI-D are superlight https://bmwi.bimmerpost.com/forums/s....php?t=1327678

OK you got me there, for the dough I spent, I could have sprung for $2k a wheel and got the BBS for only $1200 total more. I would have to go 245 in front, tho, due to the 8.5" width. And as you said, that adds back a couple pounds because of the wider tire. but the rear, I could also use a 245 and lose all the weight over stock. (maybe I still will :-)

That said, the 20" wheel choices page shows them as being in the 8.4kg range, not lighter than the 516s which you mention are 7.9kg.

https://bbs-japan.co.jp/en/products/1108/

which puts them in the 18.5 lb range. Still that would be amazing.

I sure would like to see someone put a 516 on a scale and show me. I have a hard time believing it is in the 17 1/2 lb range.

the only reference I can find on the web is this:

https://www.facebook.com/i8Procar/ph...2845716719486/

[mws]

Originally Posted by Emon Crew

Does anyone know the weight of the stock W style 20" wheels? As in how much does each wheel weigh without a tire? with the tire?

I weighed my stock 625 wheels with a digital hanging fish scale.

front 24.32 lbs
rear 25.28

wheels and stock S001 tires
front 45.5 lbs
rear 49 lbs

[stressdoc]

Mea culpa, 7.9kg is not correct for 516s. Bad data on that website. 20.3 lbs front 21.8 rear. Bi-colors are a touch lighter.

[mws]

Originally Posted by stressdoc

Mea culpa, 7.9kg is not correct for 516s. Bad data on that website. 20.3 lbs front 21.8 rear. Bi-colors are a touch lighter.

OK yeah, that sounds more reasonable for the 516, and still.... QUITE light, comparatively speaking. I am not a fan of the styling of the 516, but if I needed a weekend track set that was not expensive, I would buy a set without hesitating.

I had a side question about the 516 weight, with a BMW genius at the Mt. View dealer and he came up with this:

https://www.bmwpartsdeal.com/parts/b...106880106.html

about 41.5 lbs for a pair. so, divide by two.

Even if the literature says they are --or are not-- forged, they MUST be fully forged, at that weight. The Genius says they are likely made by BBS for BMW.

now, that said, the other BBS wheels you mentioned; the RI-Ds, would be the way to go, if

1] I was able to stomach the 5-split fork design, which I am not a huge fan of (although I know it is the lightest possible format for a light wheel)

2] money were no object.

I agree, BMW 516s for the Weight Weenie Win™

[stressdoc]

I got titanium lug nuts to save a hundred grams per wheel... Offset the additional weight of the wider Michelins...

Not that I would mess with the system, but does anyone know if regenerative braking adds unsprung weight?

[lovemycar]

Originally Posted by Bull30

I'm new to the i8 community and just had a set of Michelin Pilot Super Sport tires installed on my i8... 275/35-20 Rear and 245/40-20 front and they fit perfectly with no rubbing... Thanks to those that paved the road ahead of me... It's like a different car now that the BF Goodrich tires are gone...

On the stock rims?

[Coastali8]

Yes… those tire sizes will fit on stock rims with no clearance issues.

[tommyb13662]

No clearance issues, but I feel there is some affect to tire ability/grip. Yes my 245 front and 275 rear improved launches greatly much less slip. Cornering I feel less confident even with increased grip. The tires just have an awkwardfeel. Perhaps it's the khumo tires perhaps it's the improper fit to rim. Never ran these tires before so I can't say.

Edit:

It's the tires. I'm very disappointed in these khumo tires. When they break free they hop more than slide. It's very disconcerting. The grip level is quite high but breaks quick and no warning. Feels like the tires are hopping not sliding.

[thesubmitter]

So the HREs fit!

HRE S201s with MPSS4


These were the specs

21" x 8.5 front +30
21" x 10.5 rear +38

295/25R21
255/30R21

Quite a bit of poke in the back wheels but everything looks like it fits

[tommyb13662]

Any rub from hard driving or cornering? I always liked the look of a bit of poke. Still prefer the pre lci hood though. But yours looks sharp on those wheels.

[thesubmitter]

No issues at all even on bumps or at speed as far as i can tell. I am really happy with them especially since i paid 4500$ CAD for top of the line in like new conditio n tires and wheels . When i was running the numbers i think the radius might have been less than my winters which were 245/50/20s and i think that also helps (more travel aoaxe to the fender. They look way better in person!

[tommyb13662]

If you guys are looking for performance over looks. I now recommend 18" lightweight rims. 235/40r18, 265/35r18 rear. I dropped 11lbs per corner front and 12 lbs a corner rear over stock rims with 245/40r20, 275/35r20. Cornering is much more direct. Suspension crisper. it really pushes me back even more so than when I had it tuned. 18x8 et27 front 18x9 et45 rear. I thought it felt under damped even in sport before. Now the change is really nice. I finally like the way the car handles. Was gonna spend a few k redoing the suspension to make it feel sporty but not sure I need to now. Overall this has been the best bang per$ on this car.

[mws]

Originally Posted by tommyb13662

If you guys are looking for performance over looks. I now recommend 18" lightweight rims. 235/40r18, 265/35r18 rear. I dropped 11lbs per corner front and 12 lbs a corner rear over stock rims with 245/40r20, 275/35r20. Cornering is much more direct. Suspension crisper. it really pushes me back even more so than when I had it tuned. 18x8 et27 front 18x9 et45 rear. I thought it felt under damped even in sport before. Now the change is really nice. I finally like the way the car handles. Was gonna spend a few k redoing the suspension to make it feel sporty but not sure I need to now. Overall this has been the best bang per$ on this car.

question: I am all for losing weight, but I also compare tire weights. Did you weigh wheel and tire together before and wheel and tire together, after? I am thinking 18" tires might weigh more than equivalent circumference 20" tires.

if you did not get that opportunity, then you can look up your before and after tires on tire rack.com and look at the details on each tire and get weights. Or at least, very close weights.

also, what did you tune your i8 with?

[tommyb13662]

My biggest goal was improving auto X times. My first autox car was a Miata. Came with 18" when I bought it. When I borrowed a set of 15" were same 225 width but much much smaller diameter. Massive drop in track times. Then on my Audi TTS took off the 21" and put the stock 19" with same 265/30 profile tires. Dropping the diameter again boosted accel and dropped lap times. On the i8 I swapped from the runflats to the khumo. Just dropping the weight didn't help the feel, but Did improve grip. I'm surprised how much it improved the feel and accel going form 20 to 18".

[thesubmitter]

Originally Posted by tommyb13662

My biggest goal was improving auto X times. My first autox car was a Miata. Came with 18" when I bought it. When I borrowed a set of 15" were same 225 width but much much smaller diameter. Massive drop in track times. Then on my Audi TTS took off the 21" and put the stock 19" with same 265/30 profile tires. Dropping the diameter again boosted accel and dropped lap times. On the i8 I swapped from the runflats to the khumo. Just dropping the weight didn't help the feel, but Did improve grip. I'm surprised how much it improved the feel and accel going form 20 to 18".

I havent been able to lose grip on my new setup so far

[tommyb13662]

The rims where only about 3lbs lighter each. The rest of the weight was the tires 18" were a whole lot lighter than the 20". I think the rotational forces from 18" are a lot less than the 20". Since the most weight from a wheel/tire is the outer edge that rides on the road. So is much easier to spin up and also slow down.