Arm
Posts: 161
Joined: Tue Jan 07, 2020 5:53 pm

Tire Pressures

Tue Sep 14, 2021 11:04 pm

Hey Folks:

Can anyone verify that the 2018 i3s BEV and 2019 i3s BEV have the same tire pressures of 33/41?

I have a 2019 i3s REX and the tire pressures are quite a bit higher...particularly on the front. For this car it's 39/44.

I'm curious why such a large difference?

Thanks

eNate
Posts: 780
Joined: Mon Sep 09, 2019 5:33 pm

Re: Tire Pressures

Wed Sep 15, 2021 12:11 am

Those are all 175 & 195/20 on the S models, right? No 19s?
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Arm
Posts: 161
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Re: Tire Pressures

Wed Sep 15, 2021 12:13 am

Correct.

Arm
Posts: 161
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Re: Tire Pressures

Wed Sep 15, 2021 9:22 pm

So does anyone have an idea why??

Joff
Posts: 76
Joined: Wed Jan 02, 2019 2:44 am

Re: Tire Pressures

Fri Sep 17, 2021 7:23 pm

I think they all need higher pressures, but especially the 20 inch rims, as they have less distance to go before the rim bottoms out on a pot hole.

eNate
Posts: 780
Joined: Mon Sep 09, 2019 5:33 pm

Re: Tire Pressures

Fri Sep 17, 2021 7:36 pm

Huh, I'm confused. I expected to find a chart of 19 vs. 20, i3 vs i3S, REX vs. BEV, but instead I'm just finding one combo for the i3, another for the i3S, and they seem to change from user report to user report, but nowhere am I finding a comprehensive breakdown for what and why.
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Arm
Posts: 161
Joined: Tue Jan 07, 2020 5:53 pm

Re: Tire Pressures

Fri Sep 17, 2021 10:08 pm

eNate wrote:
Fri Sep 17, 2021 7:36 pm
Huh, I'm confused. I expected to find a chart of 19 vs. 20, i3 vs i3S, REX vs. BEV, but instead I'm just finding one combo for the i3, another for the i3S, and they seem to change from user report to user report, but nowhere am I finding a comprehensive breakdown for what and why.
Yet it's confusing or illogical. Clearly BMW increased the tire pressures for 2019 and on. Not sure why and begs the question if I should be running my 2018 i3s at the new tire pressure levels.

alohart
Posts: 2450
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Location: Honolulu, HI

Re: Tire Pressures

Sat Sep 18, 2021 4:28 am

Joff wrote:
Fri Sep 17, 2021 7:23 pm
I think they all need higher pressures, but especially the 20 inch rims, as they have less distance to go before the rim bottoms out on a pot hole.
I agree. Since buying our i3 in 2014, I have increased the inflation pressures of our 19" tires by 10 psi over the recommended pressures of 33F/41R. The inflation pressure of the rear tires then matches the maximum inflation pressure embossed on the sidewall of 51 psi. Another advantage is a slightly lower rolling resistance and thus slightly greater range. Disadvantages include a slightly rougher ride and a smaller contact patch which reduces traction a bit. I regularly measure tread depth across the tread's width and haven't measured any unusual tire wear.

Many of us in the 1st generation Honda Insight community increased the inflation pressures of the Bridgestone low rolling resistance tires installed by Honda on our Insights without any negative consequences that I'm aware of. That experience makes me confident in doing so on our i3.
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Arm
Posts: 161
Joined: Tue Jan 07, 2020 5:53 pm

Re: Tire Pressures

Sat Sep 18, 2021 9:58 am

Joff wrote:
Fri Sep 17, 2021 7:23 pm
I think they all need higher pressures, but especially the 20 inch rims, as they have less distance to go before the rim bottoms out on a pot hole.
So you're suggesting that BMW has under-estimated the i3 tire pressures up through 2018?

Joff
Posts: 76
Joined: Wed Jan 02, 2019 2:44 am

Re: Tire Pressures

Mon Sep 20, 2021 1:19 pm

Arm wrote:
Sat Sep 18, 2021 9:58 am
Joff wrote:
Fri Sep 17, 2021 7:23 pm
I think they all need higher pressures, but especially the 20 inch rims, as they have less distance to go before the rim bottoms out on a pot hole.
So you're suggesting that BMW has under-estimated the i3 tire pressures up through 2018?
Rather than say they made a "mistake" I would prefer to say the made a "decision" based on their priorities. They want the car to feel nice (not harsh) to people test driving the I3 for the first time, so that they buy the thing. MY priority is to have less tire and rim damage, more range, and cooler tires that last longer.

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