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 baffled as to why the change given the cars are pretty much identical in all aspects…even weight.
You’ll want to post this on a BMW i3 forum, that’s a really model-specific question. If the sticker on your car specified 39/44, then that’s what I’d use.
On my car it’s 33/41. It changed to 39/44…which is considerably higher.
I tried finding the i3 forum in the pull-down menu and it’s not available. So I couldn’t post it there.
But more importantly, I would like know the reason for the change. The dealer can’t answer this question which is mind-boggling to me.
Why does it matter?
If the sticker on the door jamb and the owner’s manual both say 39/44, just go with it.
It matters to me because I’m interested to know.
The REX model has a 2 cylinder range extender engine and is heavier the the base electric model.
There is no difference between the REX and BEV model tire pressures. The only change is due to model year.
There is not a I3 forum here . A simple web search will find you one. If the door plaque says what pressure to use that is all you need to know.
Nevermind. I don’t think I’ll have a productive conversation here. Incredible.
Are you surprised that a general car forum doesn’t have information about a very specific question on a car with limited sales? You just need to google ‘BMW i3 forum’ to find owners that might, or might not, have any information. The question you’re asking would really need to be answered by a BMW suspension/tire designer, but good luck finding one to contact.
A guess… it was done to improve the range of the vehicle. Higher pressures in the tires will give lower rolling resistance and better mpgs/ev range. Likely the tire spec changed as well. Not the size, the design spec of the tire.
Remembering when they wanted to change to 10k oil changes not based on mfg desires, but on conserve oil desires. Probably not a huge deal but sometimes politics over rules.
Not sure what oil change distance has to do with tire pressure .
Barkydog was just pointing out that changes in specs are sometimes due to political pressures that have nothing to do with vehicle engineering parameters.
According to Tire Guides, there was no change in tire pressures from 2018, 2019, and 2020. For a BMW i3. But they don’t delineate an REX model and maybe that is the difference.
Normally when an OEM increases inflation pressure, they are doing it because the weight increased, or they have a handling issue they are trying to solve, or something like that. In this case - like Mustangman said - I wonder if there was a tire size change. There has been a lot of activity lately on that front - new sizes, new types of loading, etc. I doubt very much anyone here or outside of the BMW design department would know.
Sometimes this is the wrong forum for the pursuit of knowledge for knowledge’s sake.
Straying from some unwritten charter can draw a scolding.
Hi Amatevosian:
While that may be an understandable sentiment, I encourage you to pay attention to CapriRacer’s reply above, especially his last sentence. He worked for years in the engineering dept of a major tire manufacturer and dealt with car manufactures on all types of tire issues like this.
I think @amatevosian_177230 thought we had an i3 specific forum or subforum:
which would likely have a better answer for such a model specific question.
BTW @amatevosian_177230 that particular drop down menu simply tags the car’s make and model to the post to assist people in the future if they’re searching for specific topics.
OK, so here’s a link that took me about 1 minute to find. Whether your particular question has already been answered I don’t know, but join up and ask there.
The OP’s already on there, under the technical section of the forum,
https://www.mybmwi3.com/forum/viewtopic.php?f=11&t=17490