START:
Overall utilization of 6.5% with 1 account at 78% ==>
FICO8 EQ 713 TU 733 EX 714
FICO9 EQ 774 TU 769 EX 765
FICO Auto 8 EQ 709 TU 728 EX 705
FICO Bankcard 8 EQ 717 TU 743 EX 725
Mortgage FICO4 TU 730 FICO5 EQ 686 FICO2 EX 694
CHANGE:
Overall utilization drop from 6.5% to 0.4 % + single-card drop from 78% to 0 ==>
FICO8 EQ 721 (+8) TU 736 (+3) EX 725 (+11)
FICO9 EQ 794 (+20) TU 799 (+30) EX 775 (+10)
FICO Auto 8 EQ 717 (+8) TU 731 (+3) EX 716 (+11)
FICO Bankcard 8 EQ 725 (+8) TU 753 (+10) EX 742 (+17)
Mortgage FICO5 EQ 695 (+9) FICO4 TU 731 (+1) FICO2 EX 703 (+9)
FICO8 simulator had predicted that the change would add 10 points to EQ and EX, and 5 points to TU
Thanks for the update.
So the sarcastic takeaway is that maxing out a card to 78% "killed" your score 
By 10 points.
There is a lot of advice floating around with lots of finger wagging that maxing out a card should never be done. I think if there's a reason to, and an ability to pay, maxing out a card is not an everywhere and always bad thing. It is something to avoid if you can, but life happens.
@NRB525 wrote:Thanks for the update.
So the sarcastic takeaway is that maxing out a card to 78% "killed" your score
There is a lot of advice floating around with lots of finger wagging that maxing out a card should never be done. I think if there's a reason to, and an ability to pay, maxing out a card is not an everywhere and always bad thing. It is something to avoid if you can, but life happens.
SJ - Good data points. Your file shows some significant sensitivity [nominally a 10 to 20 point shift] due to high utilization on one card.
I would say 78%, while a fairly high utilization, is well below my understanding of "max out" - which is likely above 90%. High utilization often results in points deduct. However, what I have read suggests an added deduct is imposed once a 90% "max out" condition is crossed. No plans to test this myself.
Here's part of an old table from Fico. It's simplified to illustrate impact by score but, scorecard is perhaps more important. Impact of high UT% on thin/new file expected to be much greater than thick/aged at the same "before" starting score. A Fico presentation I came across also suggests dirty scorecards may weigh utilization less than clean files.
Credit Mistake | If your FICO score is 680 | If your FICO score is 780 |
Maxed Out Credit Card | Down 10-30 points | Down 25-45 points |
30-Day Late Payment | Down 60-80 points | Down 90-110 points |
Source: FICO |
Borrowers already knew that late payments hurt their credit scores, but for the first time, they now know the extent of that damage.
Maxed Out Credit Card – It may surprise some to learn that maxing out a credit card could lower your score. The reason is that historical data indicates that a maxed out card is an indication of financial stress. While not everybody who reaches their credit card limit is in financial trouble, many are. This is another reason to take advantage of balance transfer credit cards even while you are working to get out of credit card debt. A balance transfer can help you spread your credit card debt over more cards and allow you to benefit from a 0% introductory rate at the same time.
30-Day Late Payment – This is undoubtedly the most common of credit mistakes, and sometimes falling behind on your payments leads to other mistakes on this list. Even if you can only make the minimum credit card payment, it’s better than racking up late fees and possibly over-the-limit fees, all while hurting your credit score. Note that in most cases, being a few days late will not be reflected on your credit report because many creditors only report late payments that are more than 30 days overdue.
@Thomas_Thumb wrote:
@NRB525 wrote:Thanks for the update.
So the sarcastic takeaway is that maxing out a card to 78% "killed" your score
There is a lot of advice floating around with lots of finger wagging that maxing out a card should never be done. I think if there's a reason to, and an ability to pay, maxing out a card is not an everywhere and always bad thing. It is something to avoid if you can, but life happens.
SJ - Good data points. Your file shows some significant sensitivity [nominally a 10 to 20 point shift] due to high utilization on one card.
I would say 78%, while a fairly high utilization, is well below my understanding of "max out" - which is likely above 90%. High utilization often results in points deduct. However, what I have read suggests an added deduct is imposed once a 90% "max out" condition is crossed. No plans to test this myself.
Here's part of an old table from Fico. It's simplified to illustrate impact by score but, scorecard is perhaps more important. Impact of high UT% on thin/new file expected to be much greater than thick/aged at the same "before" starting score. A Fico presentation I came across also suggests dirty scorecards may weigh utilization less than clean files.
Credit Mistake
If your FICO score is 680
If your FICO score is 780
Maxed Out Credit Card
Down 10-30 points
Down 25-45 points
30-Day Late Payment
Down 60-80 points
Down 90-110 points
Source: FICO
Borrowers already knew that late payments hurt their credit scores, but for the first time, they now know the extent of that damage.
Maxed Out Credit Card – It may surprise some to learn that maxing out a credit card could lower your score. The reason is that historical data indicates that a maxed out card is an indication of financial stress. While not everybody who reaches their credit card limit is in financial trouble, many are. This is another reason to take advantage of balance transfer credit cards even while you are working to get out of credit card debt. A balance transfer can help you spread your credit card debt over more cards and allow you to benefit from a 0% introductory rate at the same time.
30-Day Late Payment – This is undoubtedly the most common of credit mistakes, and sometimes falling behind on your payments leads to other mistakes on this list. Even if you can only make the minimum credit card payment, it’s better than racking up late fees and possibly over-the-limit fees, all while hurting your credit score. Note that in most cases, being a few days late will not be reflected on your credit report because many creditors only report late payments that are more than 30 days overdue.
Edited and revised 4/18/16, 9:12 AM:
Lost in the shuffle was the reduction in the overall utilization figure.
The way I'd originally planned it I was going to test 2 separate events, the first of which consisted of dropping $1000 from one low utilization card which would have brought overall utilization down from 6.5% to 5.8%. The FICO 8 simulator predicted as much or more benefit from that event than from the subsequent reduction of the 78% card to zero (and overall reduction from 5.8% to .4%)
Unfortunately, the 2 events wound up reporting together on the same day on the Experian site, so my plan had to be abandoned. But the reduction in overall utilization was reported on that site before the 78% card reduction was reported. I was able to detect the 2 events as separate on EX, and it appears that all of the points gained in FICO8 were attributable to the crossing of the 6% overall line.
On the MyFICO site, the alert which contained the 11 point increase in EX was dated 4/15/16 and stated that overall balances had decreased $996.
The alert which contained the news that the $7800 single-card balance had gone was dated 4/16/16 and contained no point change.
So, I'll never know for sure, because it happened too quickly, but I'm of the view that 6% overall utilization was a major threshold.
Update 4/18/16
Lost in the shuffle was the reduction in the overall utilization figure.
The way I'd originally planned it I was going to test 2 separate events, the first of which consisted of dropping $1000 from one low utilization card which would have brought overall utilization down from 6.5% to 5.8%. The FICO 8 simulator predicted as much or more benefit from that event than from the subsequent reduction of the 78% card to zero (and overall reduction from 5.8% to .4%)
Unfortunately, the 2 events wound up reporting together on the same day on the Experian site, so my plan had to be abandoned. But the reduction in overall utilization was reported on that site before the 78% card reduction was reported. I was able to detect the 2 events as separate on EX, and it appears that all of the points gained in FICO8 were attributable to the crossing of the 6% overall line.
On the MyFICO site, the alert which contained the 11 point increase in EX was dated 4/15/16 and stated that overall balances had decreased $996.
The alert which contained the news that the $7800 single-card balance had gone was dated 4/16/16 and contained no point change.
So, I'll never know for sure, because it happened too quickly, but I'm of the view that 6% overall utilization was a major threshold.