Forum for the entire range of BMW electric vehicles
Random lines
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW i8 Forums BMW i8 General Discussion

Post Reply
 
Thread Tools Search this Thread
      03-29-2021, 11:08 PM   #45
mws
Enlisted Member
0
Rep
41
Posts

Drives: BMWs: i8, M6, 760Li, X5M
Join Date: Sep 2015
Location: Gilroy, CA

iTrader: (0)

because, you get the single best "rear-view mirror" view of any car...

Appreciate 0
      04-01-2021, 08:13 PM   #46
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

Steering feel improves with Michelins in lower profile, slightly wider sizes.
Appreciate 0
      04-02-2021, 08:00 AM   #47
BigT
Private First Class
Switzerland
105
Rep
194
Posts

Drives: I12 i8 Coupe / I01 i3 60Ah Rex
Join Date: Nov 2008
Location: Zurich

iTrader: (0)

Quote:
Originally Posted by BanjoPaterson View Post
I believe the 0-100km/h time for the i8 was benchmarked against the 2014 Porsche 911 Carrera, which had a time of 4.6s as opposed to the i8's 4.4s. Even the 2014 Carrera 4s has a listed 0-100km/h time of 4.3s. However, both 911s have a higher top speed and would probably be better on the track (I'm guessing)
...
.
That is the correct view of the facts. Of the 911s from 2011-2019 (991), only the GT3 , R and Turbos are faster (see Wiki). But in the end, that doesn't matter either, because during my trip to Germany, I noticed how many Porsches willingly cleared the fast lane on the autobahn. Out of Respekt or rather curiosity? It doesn't really matter, does it?
Appreciate 0
      04-02-2021, 02:14 PM   #48
Obioban
Emperor
1149
Rep
2,530
Posts

Drives: 05 M3, 04 M3iT , 01 M5, 17 i3
Join Date: Apr 2008
Location: West Chester, PA

iTrader: (0)

Garage List
2017 BMW i3  [0.00]
2005 BMW M3 Coupe  [0.00]
2004 BMW M3 Wagon  [0.00]
2001 BMW M5  [0.00]
Quote:
Originally Posted by r6_philly View Post
Does that not cause more rolling resistance?

My i3 has skinny tires, but the steering actually feels more connected. Usually any issues can be improved with wheel/tire changes of course, I am just surprise that's the level of feel they settled on, especially after a few years of feedback/data. It makes it feel less "sporty" and more "comfort." Which is not a bad thing necessarily.
Wider tires decrease feel 100% of the time.

But, the issue is the EPS system— not the tires. The i3 kinda has some feel (still not great) because it barely needs any power steering assist— crazy narrow tires on a crazy light car (BEV i3 is 500-800 lbs lighter than the i8, depending on the year/options of each).
Appreciate 0
      04-03-2021, 12:24 PM   #49
Coastali8
Second Lieutenant
United_States
89
Rep
218
Posts

Drives: 2015 Crystal White Giga World
Join Date: Jul 2017
Location: Oregon

iTrader: (0)

Garage List
2015 BMW i8  [0.00]
1970 Porsche 914-6  [0.00]
2018 BMW i3s REx  [0.00]
Quote:
Originally Posted by Obioban View Post
Wider tires decrease feel 100% of the time.

But, the issue is the EPS system— not the tires. The i3 kinda has some feel (still not great) because it barely needs any power steering assist— crazy narrow tires on a crazy light car (BEV i3 is 500-800 lbs lighter than the i8, depending on the year/options of each).
I don’t quite understand your statement about wider tires decreasing feel.

I would equate “feel” with a better connection of the car to the road regardless of the EPS. The tires still transfer a different feel to the driver when width is increased.

Vehicles generally benefit from an increase in tire width. Using a wider size while maintaining the same overall diameter is known as “plus-zero” sizing. It results in a wider contact patch which provides better lateral grip, more grip on hard braking, and less vehicle roll in corners.

Last edited by Coastali8; 04-03-2021 at 12:33 PM..
Appreciate 0
      04-04-2021, 06:26 PM   #50
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

Skinny narrow tires chosen for Eco do not -> feel.
Michelin PS4s are better rubber. The steering is a tad 'heavier' with wider sizes, but 'feel' is improved as long as unsprung weight is not increased.

Part of the steering and handling feel of the i8 stems from the superb stiff chassis.
It is not a Lotus super-7 nor even a Cayman S, but the steering is very precise for AWD.

IMO the LCI is much improved from earlier versions, particularly in sport mode.

Weight reduction helps.
Appreciate 0
      04-05-2021, 06:31 AM   #51
Obioban
Emperor
1149
Rep
2,530
Posts

Drives: 05 M3, 04 M3iT , 01 M5, 17 i3
Join Date: Apr 2008
Location: West Chester, PA

iTrader: (0)

Garage List
2017 BMW i3  [0.00]
2005 BMW M3 Coupe  [0.00]
2004 BMW M3 Wagon  [0.00]
2001 BMW M5  [0.00]
Quote:
Originally Posted by Coastali8 View Post
I don’t quite understand your statement about wider tires decreasing feel.

I would equate “feel” with a better connection of the car to the road regardless of the EPS. The tires still transfer a different feel to the driver when width is increased.

Vehicles generally benefit from an increase in tire width. Using a wider size while maintaining the same overall diameter is known as “plus-zero” sizing. It results in a wider contact patch which provides better lateral grip, more grip on hard braking, and less vehicle roll in corners.
Wider tires don’t have more grip inherently. Wider tires let you run lower tire pressures without overheating your tires, and lower tire pressures give you more grip. A wider tire run at the same tire pressure has the same contact patch as a narrower tire (just wider instead of longer), and no grip increase.

Please explain how wider tires result in less vehicle roll in corners— never heard that one before...

Quote:
Originally Posted by stressdoc View Post
Skinny narrow tires chosen for Eco do not -> feel.
Michelin PS4s are better rubber. The steering is a tad 'heavier' with wider sizes, but 'feel' is improved as long as unsprung weight is not increased.

Part of the steering and handling feel of the i8 stems from the superb stiff chassis.
It is not a Lotus super-7 nor even a Cayman S, but the steering is very precise for AWD.

IMO the LCI is much improved from earlier versions, particularly in sport mode.

Weight reduction helps.
Tire variety can improve feel (stiffer sidewalls in particular), but holding everything constant other than width, going wider decreases feel. That said, the PS4Ss are a huge step better— I don’t doubt you increased feel going to them, even if you increased width at the same time.

The i8 steering is absolutely precise and accurate, no argument there. It’s only feel where it sucks.

Weight reduction is the best mod for every car
Appreciate 0
      04-05-2021, 08:57 AM   #52
Coastali8
Second Lieutenant
United_States
89
Rep
218
Posts

Drives: 2015 Crystal White Giga World
Join Date: Jul 2017
Location: Oregon

iTrader: (0)

Garage List
2015 BMW i8  [0.00]
1970 Porsche 914-6  [0.00]
2018 BMW i3s REx  [0.00]
Quote:
Originally Posted by Obioban View Post
Wider tires don’t have more grip inherently. Wider tires let you run lower tire pressures without overheating your tires, and lower tire pressures give you more grip. A wider tire run at the same tire pressure has the same contact patch as a narrower tire (just wider instead of longer), and no grip increase.

Please explain how wider tires result in less vehicle roll in corners— never heard that one before...
Really?
I give up.
Appreciate 1
      04-08-2021, 09:31 PM   #53
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

Tire Rack did some informative testing of cornering grip with different tire sizes. Gist of the results is slight increases in tire width with reduced profile do increase cornering g. But suspension/handling design is complex, and increasing tire width more than one size does not improve grip.

"Feel"? Not sure how to measure that. Not a fan of go-kart every pebble in the road 'feel'. What I enjoy is informative feedback from the steering wheel that helps me get closer to the perfect lap. I want the tires to talk to me. IMO, my i8 is better than my previous M3 in that regard.
Appreciate 1
Nachbar665.50
      04-09-2021, 09:38 AM   #54
Nachbar
Lieutenant
Nachbar's Avatar
Switzerland
666
Rep
560
Posts

Drives: i8
Join Date: Jul 2015
Location: Switzerland

iTrader: (0)

Quote:
Originally Posted by stressdoc View Post
Tire Rack did some informative testing of cornering grip with different tire sizes. Gist of the results is slight increases in tire width with reduced profile do increase cornering g. But suspension/handling design is complex, and increasing tire width more than one size does not improve grip.

"Feel"? Not sure how to measure that. Not a fan of go-kart every pebble in the road 'feel'. What I enjoy is informative feedback from the steering wheel that helps me get closer to the perfect lap. I want the tires to talk to me. IMO, my i8 is better than my previous M3 in that regard.
Same here (feel M3 vs i8)
Appreciate 0
      04-09-2021, 02:46 PM   #55
Obioban
Emperor
1149
Rep
2,530
Posts

Drives: 05 M3, 04 M3iT , 01 M5, 17 i3
Join Date: Apr 2008
Location: West Chester, PA

iTrader: (0)

Garage List
2017 BMW i3  [0.00]
2005 BMW M3 Coupe  [0.00]
2004 BMW M3 Wagon  [0.00]
2001 BMW M5  [0.00]
I believe you if your previous M3s were F8Xs. :P
(also EPS, but wider tires and heavier car)
__________________
Appreciate 0
      04-09-2021, 09:42 PM   #56
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

We have been drifting a bit off topic here... but a few more thoughts. 'Grip' depends on friction between tire rubber and road. More tire contact patch can increase grip up to a point - e.g., wider tires slide more easily on ice. All things being equal, if tires on the outer side of a curve have more grip, the car will lean more, higher g.

And yes, we are comparing recent (F80) M3s. Discussing which M3 had best steering feel and handling deserves a pitcher of really good cold beer. I would love to have a pristine E36. I still miss my 2002tii...
Appreciate 0
      04-09-2021, 09:53 PM   #57
MGRMLN
Private
5
Rep
70
Posts

Drives: 2015 Nissan GT-R Black Edition
Join Date: Nov 2009
Location: Atlanta, GA

iTrader: (0)

Mine is a daily driver

Most simply, it's more efficient than a Prius when I want it to be. In comfort mode, I can waft to work in a blend of gas and electric. And while not a rocket off the line, on the highway, this car is a killer. Passing power is never and issue. And, when I want it to be, it can transform into a very quick, yet still very comfortable Gran Turing car.
No other car can meet all of these demands so stylishly. I love mine and don't see anything close to the design brief right now except for the very spendy McLaren Artura.
__________________
2015 Protonic Blue BMW i8 Pure Impulse Edition
2015 Black Nissan GT-R Black Edition
2019 Carrara White Porsche Cayenne
Appreciate 0
      04-10-2021, 08:54 PM   #58
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

Quote:
Originally Posted by MGRMLN View Post
Most simply, it's more efficient than a Prius when I want it to be. In comfort mode, I can waft to work in a blend of gas and electric. And while not a rocket off the line, on the highway, this car is a killer. Passing power is never and issue. And, when I want it to be, it can transform into a very quick, yet still very comfortable Gran Turing car.
No other car can meet all of these demands so stylishly. I love mine and don't see anything close to the design brief right now except for the very spendy McLaren Artura.
Well put. Agree with all.
Appreciate 0
      04-11-2021, 04:08 PM   #59
Obioban
Emperor
1149
Rep
2,530
Posts

Drives: 05 M3, 04 M3iT , 01 M5, 17 i3
Join Date: Apr 2008
Location: West Chester, PA

iTrader: (0)

Garage List
2017 BMW i3  [0.00]
2005 BMW M3 Coupe  [0.00]
2004 BMW M3 Wagon  [0.00]
2001 BMW M5  [0.00]
Quote:
Originally Posted by stressdoc View Post
We have been drifting a bit off topic here... but a few more thoughts. 'Grip' depends on friction between tire rubber and road. More tire contact patch can increase grip up to a point - e.g., wider tires slide more easily on ice. All things being equal, if tires on the outer side of a curve have more grip, the car will lean more, higher g.

And yes, we are comparing recent (F80) M3s. Discussing which M3 had best steering feel and handling deserves a pitcher of really good cold beer. I would love to have a pristine E36. I still miss my 2002tii...
Makes sense-- F8X is the only M3/4 with garbage steering (well, probably the new one, too), as the only EPS version-- and it's heavier than an i8, with wider tires (both with for steering feel). So, I think that's accurate-- the i8 has marginally better steering feel than the F8X M3/4, and WAY worse steering feel than any M3 prior to it.

That said, if you look at the physics equation for the force of fiction:
F=μN
(verify here: https://sciencing.com/calculate-forc...n-6454395.html )

Translated:
(Force of friction) = (coefficient of friction) X (normal force)

Further translated:
(Tire grip) = (tire compound) x (weight of car)

Obviously a heavier car also places more load on the car under cornering, so making a car heavier doesn't make it grip better. But, that is why downforce works so well-- increasing the grip without increasing the cornering load.

Wider tires do worse on snow because they make it easer to effectively hydroplane (on the snow)-- the wider (but shorter) contact patch means more snow has to be displaced or driven on top of.
__________________
Appreciate 0
      04-13-2021, 01:42 PM   #60
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

I have driven every M3. Not sure why you say the i8 is WAY worse. I prefer the steering feel of the i8 to all M3s from the E90 on. I prefer it to a C4 Porsche 996. Every Audi and MB that I have driven. If I were giving out grades, it would get an A-/B+. It is arguably one of the best steering AWDs on the road.

But I don't know of any 'objective' measures of steering feel, so to each their own.
Appreciate 1
      04-14-2021, 01:34 AM   #61
khlambo
New Member
14
Rep
10
Posts

Drives: 1997 Lamborghini Diablo Roadst
Join Date: Apr 2021
Location: Phoenix

iTrader: (0)

I am pulling the trigger on the 199 mile (collector car) i8 Roadster at Hubbard Motors, Scottsdale, AZ in the morning. I have two Lamborghini Diablos, so not new to this segment, just looking for any advice on i8's. Thanks KHLAMBO
Appreciate 0
      04-14-2021, 09:30 AM   #62
F5506m
Second Lieutenant
26
Rep
204
Posts

Drives: 2019 i8
Join Date: Jul 2016
Location: New Jersey

iTrader: (0)

Quote:
Originally Posted by khlambo View Post
I am pulling the trigger on the 199 mile (collector car) i8 Roadster at Hubbard Motors, Scottsdale, AZ in the morning. I have two Lamborghini Diablos, so not new to this segment, just looking for any advice on i8's. Thanks KHLAMBO
Curious what was the purchase price as I am on the fence on buying back my car.
Appreciate 0
      04-14-2021, 08:43 PM   #63
stressdoc
Moderator
stressdoc's Avatar
Dominica
525
Rep
10,764
Posts

Drives: BMW i8; Toy 4runner TRD pro
Join Date: Jun 2005
Location: Waco TX

iTrader: (0)

Quote:
Originally Posted by khlambo View Post
I am pulling the trigger on the 199 mile (collector car) i8 Roadster at Hubbard Motors, Scottsdale, AZ in the morning. I have two Lamborghini Diablos, so not new to this segment, just looking for any advice on i8's. Thanks KHLAMBO
Welcome! Get some track time in with my nephew at AMP...
Appreciate 0
      04-15-2021, 12:22 AM   #64
khlambo
New Member
14
Rep
10
Posts

Drives: 1997 Lamborghini Diablo Roadst
Join Date: Apr 2021
Location: Phoenix

iTrader: (0)

Quote:
Originally Posted by F5506m View Post
Curious what was the purchase price as I am on the fence on buying back my car.
$135K, 199 miles, basically a brand new car. Not a steal, but I thought fair. Couldn't stop smiling on the way home.
Appreciate 0
      04-15-2021, 12:10 PM   #65
khlambo
New Member
14
Rep
10
Posts

Drives: 1997 Lamborghini Diablo Roadst
Join Date: Apr 2021
Location: Phoenix

iTrader: (0)

My first non-Air Force Blue car in quite a while

My first non Air Force Blue Car in quite a while
Attached Images
     
Appreciate 1
YWGT3354.00
      04-15-2021, 12:29 PM   #66
F5506m
Second Lieutenant
26
Rep
204
Posts

Drives: 2019 i8
Join Date: Jul 2016
Location: New Jersey

iTrader: (0)

Congrats..Awesome color combination. I have a feeling the LCI cars my not do too bad. They will depreciate, but my guess would be they settle at 70k - 75k form coupes more for the roadster and non-LCI coupes around $60k - $65k.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:10 PM.




bmw
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST