Front Tire Upgrade

Has anyone tried to fit the front wheels with the wider rear tires to see if there is any clearance problems.

Love my i3 but cannot get over those skinny front tires.

Thanks.

Save your money. I applaud BMW for the wheels on the i3. They look great whether they're 19" or 20". The trade off that gives us lower rolling resistance are the thin tires. People smarter than most of us determined they're the right size tires for your i3.

The wider tire requires the wider rim. BMW uses two different rim sizes on the Tera and maybe the middle model too. So you would probably need to get two more rims to match what you already have.

DAZ said:

Save your money. I applaud BMW for the wheels on the i3. They look great whether they're 19" or 20". The trade off that gives us lower rolling resistance are the thin tires. People smarter than most of us determined they're the right size tires for your i3.

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+1!

Put it another way: look up the performance specs of a Mini Cooper S. Hint: i3 out performs in virtually all measures

Trying to make the i3 look more conventional seems like somewhat defeating the original purpose. Wider tires means more drag which means less range. If you were worried about how the car looks, you shouldn't buy an i3 in the first place!

Owning and driving an i3 requires a certain mindset - it is not conventional. Old perceptions need to change to embrace the features.

jadnashuanh said:

Trying to make the i3 look more conventional seems like somewhat defeating the original purpose. Wider tires means more drag which means less range. If you were worried about how the car looks, you shouldn't buy an i3 in the first place!

Owning and driving an i3 requires a certain mindset - it is not conventional. Old perceptions need to change to embrace the features.

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Don't like the skinny tires. Do not approach a i3 from the front or rear!

Guys, I am willing to give up a little efficiency for a decent size tire. I am aware of the advantages of the skinny tires, but just wondering if anyone has tried putting the wider rear tires on the front to see if it will rub against anything.

Thanks for your responses so far.

Like I said I love my i3......for the most part.



White Rex, Giga World 10/01/2014.

To some, a car is a passion, to others, it is an appliance. You can't see the tires while driving! While I can understand some people's desire to create a special look, I think BMW did a good cost/benefit analysis on the car as is. Maybe it's the engineer in me.

Wider tire, more weight, more drag, 1/2" isn't going to make enough difference, and while I do not know, wider, probably will have clearance issues both from lock-to-lock and bounce-rebound. Right now, the only company that makes tires to fit the i3 is Bridgestone - specially designed for grip and economy. So, with a wider wheel, your easy choice, if it would fit, is the stock 5.5" rim, and only one tire that would fit. If you have the staggered setup now, it would only take an hour or so to swap the fronts to the back and vice-versa. You'd have a good idea after a short drive, if they fit in the first place. THe narrower one will fit in the back, as it's stock on some versions...the rear MIGHT fit on the front.

Lots of talk about the low rolling resistance of larger dia higher pressure tires and how that is so superior to the old fashioned tires on a leaf or other EVs, but who here is actually running them at the factory pressures? 33psi in the front and 41psi in the rear......

If you aren't, you might as well be running a more comfortable set of higher profile rims and tires IMHO as far as EV range goes. All of the range claims and predictions are based upon having a correctly inflated set of tires, under inflate and all of that is inaccurate. Run at 30/36 front and rear and you are 15% under inflated and that will negate any range advantage from the special high pressure, large diameter, low rolling resistance wheels and tires.

19s or 20s, they all have the same pressure requirements as per the manual.

I just wish Bridgestone made a set of higher profile tires for the BMW rims to get a bit more sidewall into play.

WoodlandHills said:

Run at 30/36 front and rear and you are 15% under inflated and that will negate any range advantage from the special high pressure, large diameter, low rolling resistance wheels and tires.

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And run a higher risk of tyre and rim damage from potholes etc.

I just wish Bridgestone made a set of higher profile tires for the BMW rims to get a bit more sidewall into play.

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Higher profile on the stock rims? I think not, that would be crazy. Speedo would be way out (under reading) and tire clearance issues would surface.

And, a larger diameter assembly would also change the gearing.

The only time you could use a higher profile tire would be to go with a smaller diameter wheel and that's IF you could find one that fit without rubbing something.

THe entire tire construction, including both the carcass and the rubber and the tread design are part of the low-rolling resistance assembly. Running any tire at lower than specified pressure usually affects both handling, max load capacity, and longevity. Not a good idea.

The i3 is not a conventional car. It doesn't look conventional. It wasn't put together with conventional bits. IMHO, to fully appreciate its unique features, trying to make it look more conventional to mold it to your perception of right means maybe it wasn't the right purchase for you.

jadnashuanh said:

And, a larger diameter assembly would also change the gearing.

The only time you could use a higher profile tire would be to go with a smaller diameter wheel and that's IF you could find one that fit without rubbing something.

THe entire tire construction, including both the carcass and the rubber and the tread design are part of the low-rolling resistance assembly. Running any tire at lower than specified pressure usually affects both handling, max load capacity, and longevity. Not a good idea.

The i3 is not a conventional car. It doesn't look conventional. It wasn't put together with conventional bits. IMHO, to fully appreciate its unique features, trying to make it look more conventional to mold it to your perception of right means maybe it wasn't the right purchase for you.

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Big +1

I33t said:

WoodlandHills said:

Run at 30/36 front and rear and you are 15% under inflated and that will negate any range advantage from the special high pressure, large diameter, low rolling resistance wheels and tires.

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And run a higher risk of tyre and rim damage from potholes etc.

I just wish Bridgestone made a set of higher profile tires for the BMW rims to get a bit more sidewall into play.

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Higher profile on the stock rims? I think not, that would be crazy. Speedo would be way out (under reading) and tire clearance issues would surface.

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I don't see anything crazy about going plus 1 on tires at all. I just did it on my Infiniti and the speedo went from 4 miles optimistic to 100% accurate. The same thing happened when I went plus 1 on my truck, speedo went from optimistic to dead nuts accurate. What's not to like. If I went up one size in profile On the i3 I would probably lose the 2mph cushion in the speedo, but so what?

My car was delivered with 28psi all around and others have reported similar pressures, all lower than recommended. BTW, I check mine with a liquid filled gauge from Pegasus Racing supply that tops out at 60 psi so it normally measures in the middle of its range. The top and bottom 20% of a gauge's range are the least accurate.

jadnashuanh said:

The i3 is not a conventional car. It doesn't look conventional. It wasn't put together with conventional bits. IMHO, to fully appreciate its unique features, trying to make it look more conventional to mold it to your perception of right means maybe it wasn't the right purchase for you.

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What a load of pompous crap!

I am surprised you can see to type, what with looking so far down your nose at me.

This is just a freaking car. In not too many years they will be just another worn out used car, ready for some kid to play with. Body kit, neon, thumping bass, lowering springs and all sorts of tires. And it won't stop there, these cars will be hotrodded with bigger motors, better controllers, etc. sooner rather than later. So what!! It's just another car: putting a bit taller tires on it is not the end of the world........

And just what is it that qualifies you to judge me or anything about me in any way, much less what kind of car is the right purchase for me? In some way the fact that I am willing to trade reduced range for reduced NVH somehow enables you to make such pretentious statements about a person about whom you know nothing? Is that it? If so, can you see how ridiculous you sound?

The way I see it, you buy a car knowing its capabilities and features. The i3 went through a huge amount of what-if and why decisions on various choices to perform its stated function during development. Wanting to change that, maybe it wasn't the best purchase verses buying something that met your needs more exactly. Now, you'd likely say that there isn't anything else out there that's close, which supports my assertion that the car is somewhat unique. Name one other mass production vehicle with a CFRP body and aluminum running platform using an electric motor and batteries for propulsion...there just aren't any. You get what you get.

It will take some careful measurements to verify that a plus 1 tire size and wheel would fit. (BTW, plus 1 generally references the wheel size, with the overall diameter remaining the same, meaning a lower profile tire). Regardless, it certainly will change the gearing, and therefore your acceleration capabilities if your wheel/tire package is larger in diameter, at a decrease in total range because of increased drag. When you get to 20 or 21" wheels (or larger diameter), you rarely find them in 5 or 5.5" widths, and even 6 or 7" is rare, so good luck finding a wheel that might fit. Very few tires designed to fit those larger diameter wheels are low rolling resistance, adding to the drag.

Feel free to modify the vehicle in any way you want. It may affect your warranty, and will affect your performance depending on how far and what you do, though.

For the past 20 some years, Americas Tire/Discount Tire where I buy my tires have called going up one size on diameter plus 1. This is nothing new, my Dad went up one size back in 1963 when he put replacement tires on our 1961 Falcon. And we have never bought larger rims..... What purpose would that serve, the whole idea is to get a bit taller tire at the cheapest price for the purpose of changing the gearing and softening the ride. Two things that need improvement on this car. The ride is too damn harsh and what EV needs such a big motor and gearing that it acellerates like an M4? Finally, not everyone wants to drive a Donk......

Who cares what the car is made from? What on earth does the chassis material and body material have to do with tire choice? Are you also concerned with the interior color too?

WoodlandHills said:

For the past 20 some years, Americas Tire/Discount Tire where I buy my tires have called going up one size on diameter plus 1.

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This may be the case, but it is not the normal understanding of Plus 1 in the wider tyre industry.

Most cars will have clearance issues if the tire/wheel height is changed from design, especially if it also ends up wider, not counting the potential handling, odometer, speedometer issues. Sometimes, they will also have problems if a wider tire/wheel is chosen even with the same overall diameter. Plus or minus sizing for nearly any company refers to the wheel diameter. TO maintain the same assembly diameter, that means choosing a different aspect ratio tire. SOmetimes, you'll get better results by minus sizing, especially if you're going to go from a bigger wheel to a smaller one with winter tires. On the case for the i3, Bridgestone only makes their winter tires to fit the i3 in the 19" sizes and on the 5" wide rims. If you work out the rolling diameter of the standard and optional tires on the i3, the 20" is what the industry would call a plus 1 upgrade, but it has almost exactly the same overall diameter as the 19" stock wheel/tire assemblies. This is by design, and follows industry norms.

All of the tires, stock 19" and optional 20" available for the i3 have an assembly diameter within about 0.3" of each other. And the difference between the Giga wheel/tires and the optional 20" is closer to 0.1"

jadnashuanh said:

Most cars will have clearance issues if the tire/wheel height is changed from design

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Depends upon the size change, virtually all vehicles (except some exotic supercars) are designed with clearance for the fitting of tyre chains, usually approximately 10-15mm overall around the tyre.

If you stick to modest changes it's fine and yes it can actually help making the speedo read a more accurate indication and improve the ride slightly, it can also degrade handling slightly and of course invalidate new car warranties and breach insurance terms.

Everything in moderation will usually see you alright.

There are several more things that can come into play when changing tires and wheel sizing (wheel offset for example is one), but guys do it all the time. I owned 3 Toyota Prius vehicles and as a member of that forum for several years I have watched many threads where wheel and tire upgrades were done successfully. Clearance is the biggest issue, otherwise if it clears and the owner is not concerned about the trade off in efficiency then what really makes the difference. As to another comment about warranty, I have never seen a post on the Prius chat site where they had any warranty issues from changing wheel and tire configurations.

If anyone whats to snoop around in priuschat.com and do a search I am sure you can find a wealth of information there as to what impact changing to wider, taller, heavier..... tires/wheels will do to fuel efficiency. Believe me the guys over there, while they want to and do install nonstandard wheels/tires also discuss in great detail the impact it had on the driving characteristics of the car. Personally I prefer leaving my car stock, the engineers who designed it took a lot of things into account in it's original design, but hay it's your individual investment and you should use it and enjoy it the way you see fit as long as it is safe.

Yes it won't be long before you will see many modifications of the i3 coming up on here again and it won't stop with wheels and tires. What Woodlandhills is proposing is really quite benign in my opinion.