[i8beemz]

So far I've seen people using mainly Michelin Pilot Sport 4s and Pirelli P Zeros.

Which tires have been lasting you the longest while providing a great ride? I need something that can handle turns on canyon roads with ease. I drive in Southern California weather 90% of the time so snow isn't an issue.

I'm also debating on getting wider tires. I've seen a lot of you guys getting 245/40R20 and 275/35R20. Someone pointed out that wider tires could be an issue for the aerodynamics though. Have you guys experienced many cons with wider tires?

I also saw someone opt for 245/40/20 front and 255/40/20 rear which looked like a good combo too.

[Nachbar]

Wider tyres on stock rims look (belly) ugly.

[Coastali8]

Originally Posted by Nachbar

Wider tyres on stock rims look (belly) ugly.

Well.... that’s one opinion.
I installed Bridgestone 245’s and 275’s on the stock rims and I think the car looks much better and handles way better. The original skinny tire sizes in my opinion look dumb on the car.
I have absolutely no clearance issues.
As far as aerodynamics or increased rolling resistance affecting your gas mileage, for me it’s not measurable in normal driving.

[rastaman777]

Originally Posted by Coastal i8

Well.... that's one opinion.
I installed Bridgestone 245's and 275's on the stock rims and I think the car looks much better and handles way better. The original skinny tire sizes in my opinion look dumb on the car.
I have absolutely no clearance issues.
As far as aerodynamics or increased rolling resistance affecting your gas mileage, for me it's not measurable in normal driving.

Originally Posted by Coastal i8

Well.... that's one opinion.
I installed Bridgestone 245's and 275's on the stock rims and I think the car looks much better and handles way better. The original skinny tire sizes in my opinion look dumb on the car.
I have absolutely no clearance issues.
As far as aerodynamics or increased rolling resistance affecting your gas mileage, for me it's not measurable in normal driving.

I don't like the skinny tire look either.
My only hesitation to changing the tires is for aerodynamics/handling.
Is occasionally but regularly going 140-150mph considered normal driving ?
I'm sure it can't be a big deal not using stock tires.

[Birdland]

In my corner of the wold(Europe) it’s simply not legal to use tyres with different dimensions than is stated in the COC. In Norway we have to pay additional tax when opting for wider/bigger wheels as the Co2 emission increase and our tax system is based on the cars co2.

[patsgarageonline]

I'm running 30mm wider (and 5% lower profile) all the way around. I chose an all season tire for better traction in all weather conditions, since I daily drive my i8. I did a review of these tires after 10k miles and compared them to the original tires which also had 10k miles on them.

[MGRMLN]

I also run all seasons on my i8 since it's my daily driver throughout the year. I run a 245 square setup, Bridgestone RE980AS that totally eliminates the skinny front tire induced UNDERSTEER but doesn't introduce the additional friction drag of 275's at the rear. No rubbing issues at all.

I did swap my factory lug bolts with titanium ones that helped lower unsprung mass.

[ken997]

Originally Posted by Coastal i8

Well.... that’s one opinion.
I installed Bridgestone 245’s and 275’s on the stock rims and I think the car looks much better and handles way better. The original skinny tire sizes in my opinion look dumb on the car.
I have absolutely no clearance issues.
As far as aerodynamics or increased rolling resistance affecting your gas mileage, for me it’s not measurable in normal driving.

Can you please give us the full size of the new tires..are they
245/40x20 and 275/35x20? Thank you.

[stressdoc]

Originally Posted by MGRMLN

I also run all seasons on my i8 since it's my daily driver throughout the year. I run a 245 square setup, Bridgestone RE980AS that totally eliminates the skinny front tire induced UNDERSTEER but doesn't introduce the additional friction drag of 275's at the rear. No rubbing issues at all.

I did swap my factory lug bolts with titanium ones that helped lower unsprung mass.

Where did you get your lug bolts? Acer? Do you know specs offhand? Surprised BMW did not put titanium bolts on i8.

Thanks, I am an unsprung weight reduction junkie...

And if anyone knows a source to get the stock all black 516 rims I would be most thankful. Or BBS FI-R.

My recommendation is Michelin Pilot sport 4S, unless a) you want stock size, or b) live in NW or other rainy place; in which cases I suggest the Pirelli P-Zero.

My choice for now is Michelin PS 4S 20 235/40 and 265/35

[MGRMLN]

Originally Posted by stressdoc

Where did you get your lug bolts? Acer? Do you know specs offhand? Surprised BMW did not put titanium bolts on i8.

Thanks, I am an unsprung weight reduction junkie...

And if anyone knows a source to get the stock all black 516 rims I would be most thankful. Or BBS FI-R.

My recommendation is Michelin Pilot sport 4S, unless a) you want stock size, or b) live in NW or other rainy place; in which cases I suggest the Pirelli P-Zero.

My choice for now is Michelin PS 4S 20 235/40 and 265/35

Yes. Acer.
Bought them here:

https://smile.amazon.com/gp/product/...3400_397493790

[Coastali8]

Originally Posted by ken997

Can you please give us the full size of the new tires..are they
245/40x20 and 275/35x20? Thank you.

Yes. 245/40X20 and 275/35X20
They fit just fine on the stock wheels with no clearance issues.
Adds 30mm in width with the tire diameter and sidewall dimensions remaining almost identical to the original BMW tire choice.

[Coastali8]

Originally Posted by rastaman777

I don't like the skinny tire look either.
My only hesitation to changing the tires is for aerodynamics/handling.
Is occasionally but regularly going 140-150mph considered normal driving ?
I'm sure it can't be a big deal not using stock tires.

Well...
I’m not sure that’s normal driving or responsable driving but the speed ratings on the tires are the same as the original tires and with proper tire pressure I can’t see a problem.

[stressdoc]

Originally Posted by MGRMLN

Yes. Acer.
Bought them here:

https://smile.amazon.com/gp/product/...3400_397493790

Thanks! $309 for black... diets can be $$$. Cheaper than a set of BBS FI-R though. And a good way to offset increased weight from wider tires.

[MGRMLN]

Originally Posted by stressdoc

Thanks! $309 for black... diets can be $$$. Cheaper than a set of BBS FI-R though. And a good way to offset increased weight from wider tires.

Yes! That's exactly why I got them. I'm running 245 square setup with 3mm spacers so I wanted to offset the gains. I think the combo is still lighter than box stock.

[stressdoc]

I am about to pull the trigger on a set of Michelin PS 4S 245/35 front, 275/30 rear. a bit smaller diameter but should be OK. Any thoughts on these sizes?

[jezza211]

I run PS4 235/45/20 front and 265/40/20 rear on stock rims, perfect rolling diameter match and slightly taller gearing, same 0- 60 times but a little less snappy off the mark (keeps the wife from complaining ) nice ride on not so good roads here in Thailand.
also fills the wheel arches nicely, no spacers needed, has 5mm clearance to front upright,
ride height increase about 5mm
this set done 18,000ks and look to still have 80% whereas Pirellis were stuffed at 15,000

[norcimo]

Originally Posted by MGRMLN

I also run all seasons on my i8 since it's my daily driver throughout the year. I run a 245 square setup, Bridgestone RE980AS that totally eliminates the skinny front tire induced UNDERSTEER but doesn't introduce the additional friction drag of 275's at the rear. No rubbing issues at all.

I did swap my factory lug bolts with titanium ones that helped lower unsprung mass.

I'm trying to understand your setup.
245 all around, Got it.

You mention 3mm spacers? Is that on all 4 or just the front?

Thanks.

[MajorJump]

Originally Posted by Coastali8

Yes. 245/40X20 and 275/35X20
They fit just fine on the stock wheels with no clearance issues.
Adds 30mm in width with the tire diameter and sidewall dimensions remaining almost identical to the original BMW tire choice.

Are any spacers needed with this setup?

I’m debating this or a 245 on each corner. Both look viable, but I can’t see if any spacers out other adjustments are required?

Many thanks

[Coastali8]

Originally Posted by MajorJump

Are any spacers needed with this setup?

No