Planning on full-size spare

Hi,

I wanted to ask the community to make sure I have the technical specs correct for 2014 BMW i3-REx, 19" tires.

I am looking at:

• $138.45 - ECOPIA EP600 155/70R19 (front)
• $239.00 - RIAL X10-I, Front: 19x5
• $377.45 (not including shipping)

My understanding is a rear tire mounted on the front will impact parts of the body and steering leading to an expensive repair and tire replacement. So I've spected out a front tire and wheel from Tire Rack. My expectation is I could use this tire on the rear at least long enough to complete my trip and reach a dealer/tire shop to repair or replace the flat.

Does this agree with our understanding?

Thanks,
Bob Wilson

Hi to all owners
I live in Costa Rica and was born electric on the 13th of March. This is the perfect country for my car with short distances and perfect weather
year round. The mountains offer a small challenge manageable with the REX.
I purchased a fluid black REX with navigation, self parking, HK stereo, 2 tone gray interior, ACC,.

I am a 68 year old Canadian living in Costa Rica for the last 22 years and have worked ,and am still working as a mechanic offering mobile service as a pass time.
The BMW guaranty here is 2 years unlimited kms. The battery guaranty is 8 years 100,000 kms
I already have 2.554 kms on the car and plan on driving it as much as I can before the 2 years are up.It is such a pleasure to drive .
This is my first new car and my first BMW. i would never buy a new car with an ICE.

Now about the spare. A full size spare does not fit lying down in the back. I thought of buying a doughnut spare from another BMW model
The problem is that the I3 has a 5x112 wheel while all other BMW models use a 5x120 wheel.
i discovered that Mercedes use a 5x112 wheel so I was able to find from an after market BMW , Mercedes parts dealer a used Mercedes
spare wheel and tire (never used) for $100.00 The wheel is 17 inch and the tire is 155/70 r17.
It fits perfectly on the car without interferring with the steering or suspension .I drove over 10 kms and the tire pressure warning system did
not come on.
It just fits behind the back seat with an inch to spare with the hatch closed.

I then modified a scissor jack to fit in the rectangular cups to lift the car without damage to the body.
So I have the jack and wheel wrench in the frump and hopefully I will never have to use them

The base i3 comes with a 'square' setup...all four wheels/tires are identical. This is also what you'll get if you opt to buy a winter tire set. SO, yes, a 'front' tire/wheel on the i3 will work perfectly fine on the rear. But, if the two rear wheel/tire combinations are different, just like on any car, it could affect your emergency handling characteristics because of their differences in grip. Assuming you stick with OEM options, the OD of the two different tires are functionally identical.

FWIW, from what I've found, the i3 takes longer than many other cars (BMW included) before it will issue an error message when one wheel's TPMS is not detected. Same idea when you reset the sensors from the menu...you have to drive for awhile before they are all recognized and placed properly.

Moei3 said:

i discovered that Mercedes use a 5x112 wheel so I was able to find from an after market BMW , Mercedes parts dealer a used Mercedes
spare wheel and tire (never used) for $100.00 The wheel is 17 inch and the tire is 155/70 r17.
It fits perfectly on the car without interferring with the steering or suspension .I drove over 10 kms and the tire pressure warning system did
not come on.
It just fits behind the back seat with an inch to spare with the hatch closed.

Click to expand...

Your spare tire obviously has a smaller diameter than the standard tires. On some cars, this could cause the traction control to apply the brakes on the wheel that's rotating faster (i.e., your spare) than the other tire on the same axle. In your test drive, did you notice the traction control activating or maybe feel the brake dragging on the spare wheel?

Bob,
I understand your concern but I've driven BMW's without a spare for the past 17 years (~200K miles). Run flats were supplied with the car but I switched to go flats when they wore out. I carry a tire plug kit (and a jack ) and an el cheapo air compressor that plugs into the cigarette lighter. I got it at Wal Mart.
I also carry a few tools, like a pair of pliers to pull a nail out, screwdriver, socket and breaker bar to remove the lug nuts, etc.
Yes, I've used it a couple of times and it works well. A few times I just left the plug in and continued to drive until the tire wore out, many thousands of miles later. I've never had an issue with tire plugs. Sometimes it was sufficient to just pump up the tire until I could get to a tire shop. I guess I'd be in trouble if I got a nail or cut on the sidewall but that is a rare occurrence and has never happened to me.
Just my 2 cents, FWIW.

Thanks,

Moei3 said:

. . .
i discovered that Mercedes use a 5x112 wheel so I was able to find from an after market BMW , Mercedes parts dealer a used Mercedes
spare wheel and tire (never used) for $100.00 The wheel is 17 inch and the tire is 155/70 r17.
It fits perfectly on the car without interferring with the steering or suspension .I drove over 10 kms and the tire pressure warning system did
not come on.
. . .

Click to expand...

I was looking for something with 'longer legs.'

Thanks,
Bob Wilson

My i3 does not have the sensors in the wheels. Before buying the spare I deflated one tire by 15 lbs and drove . After a couple of kms the low pressure warning came on so , I knew that the system was working With the spare 17'" wheel and a 10 km test drive the warning did not come on and the car handled normally. Can someone tell me why the spare did not trigger the warning system?
I am car mechanic so I understand how a differential works and that would only apply if the spare was on the rear wheel.
the spare will only be used to get me to the nearest tire repair shop
During my 22 years of driving in Costa Rica the average speed of the trips has been 60kms an hour
In Costa Rica there are many tire repair shops because drivers will drive until the tires go bald in order to save money. Therefore they get a lot of flats.
From what I have learned once you inject the sealant into the tire it dissolves the rubber to seal the leak. Thus the tire has to be replaced.
Quite an expensive repair cost for a flat tire. At present my tires are only available at the BMW dealer so you and i can imagine the price.
This spare will only be used to get me to the nearest repair shop and save a good tire because it has been injected will the sealant.

Moei3

I do not know what the relative difference in circumference on the tires is that will trigger the alert. It appears that your spare hasn't exceeded that threshold. A difference in circumference on the undriven wheels isn't as big an issue as it will be on the driven wheels when it comes ultimately to wear on things like the differential. But, if you kept the speeds down and it was only used for a short distance, it's probably not an issue.