Tire Pressures

[Arm]

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]

Those are all 175 & 195/20 on the S models, right? No 19s?

 

[Arm]

Correct.

 

[Arm]

So does anyone have an idea why??

 

[Joff]

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]

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.

 

[Arm]

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]

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.

 

[Arm]

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]

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.

 

[Arm]

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.

Well I prefer the handling feel at higher tire pressures but the ride is considerably harsher. Plus, I can honestly say my 2019 i3S tires didn't last very long at 39/44. Barely got 15k out of them which I don't think is very good.