Spire expire on Dec 31, 2018 and just bought Ambassador. Now Its shown on the card on the Ap that expire on Dec 31, 2019 but when I look at the status progress I shown that I have to complete 75k or 75 nights to remain spire for 2019. Now i'm confused. which one is real? I didn't stay at IHG a lot this year so won't b able to meet the requirement. thanks

The card on the app is the Ambassador Status renewal/expiration date which you just just extended. The Spire is not shown there.
In the iOS App below "Available to redem" there is a 2018 Track to Elite Status with small arrow > click on the arrow and it opens a window stating the Elite Status Expiration (for me 12/31/2019 > the Ambassador renewal extended Spire for a Year)
BTW my tracker shows app 60k or x nights to reach Spire too but think the Ambassador renewal overwrites this tracker

Just renewed today
 

I just renewed today and had to speak with the Spire line. So I asked her when my Spire expires as I'm about 3k short. She said I'm a Spire member till Dec 31st, 2020. I asked how that could be as we haven't started a new year yet, in which she said, renewing my Ambassador extended my Spire another year.

I'm a bit confused here: does this mean you get one year of extra Spire for being Ambassador plus a second year for actually earning enough base points, where the status expires in 2020 instead of the end of 2019?

Has anyone had success in taking out Ambassador as a new member (rather than renewing) and getting Spire renewed too? I took out Ambassador last week by calling, as the 10k offer web form wasn't working for me. I got my 10k points posted a couple of days later and Spire Ambassador shows as expiring 1 Jan 2020 on web but 31 Dec 2019 in the app. However, if on the app I click through on my Elite status 2018 track it still shows Spire status expiration as 31 Dec 2018.
Do I have any hope of this changing or does Spire only extend if you are renewing Ambassador?

Not an answer to your question but in my case it's the opposite:
web: EXP. 01 JAN 2019
app: EXP. DEC 31, 2019
"2018 Track to Elite Status" in app: Elite Status Expiration 12/31/2020

I got Spire status recently and renewed Ambassador a few days later. I have no clue which of the dates above I should trust. The fact that they use three different date formats makes it even more inconsistent.

I purchased Ambassador for the first time last December and it renewed my Spire for 2018, so I wouldn't think it works only on renewal.

How bizarre DuMaInSin. I assume you mean 2020, not 2010 on that web date?

Thanks, fingers crossed it'll work for me, so long as they haven't done any IT changes that stops this.

Well the mere existence of this thread doesn't really support the "longevity" of this.

I don't think IHG is unaware of the thing or unable to fix. It is rather an unpublished benefit, motivating people to renew Ambassador. And IHG non-Amb statuses have pretty much zero hard benefits anyway. It's nothing like Marriott Platinum or even Accor Platinum.