For real world purposes I succumbed to a 5.95% 15k installment loan offer from one of my credit unions. The loan reported on TU today, causing aggregate installment loan utilization to go up to 89.2%, and dropped my TU FICO 8 a whopping 37 points!
After taking out the loan I decided I didn't like it too much, largely because of all the credit disability insurance and credit life insurance they conned me into taking out, so I'm busily paying the damned thing off. I'll update from time to time with data points.
I still have my little SSL with Alliant, so it will be optional, when I get this sucker down to 9%, whether to keep it or close it out.
The loan reported a month later on Experian, causing EX FICO 8 to drop 31 points.
Oddly, by the time the loan reported on EX it had been paid down to 9%, but for some reason the balance reported is the 89% version.
Bummer (although I guess it makes testing more interesting).
I'm all about more testing with installment loan breakpoints 
If you paid the new loan down to 9% and your SSL is < 9% already (I'm assuming) wouldn't your aggregate utilization return to the same scoring range now that it was prior to taking out this new loan? That being the case, don't you think your score will return to exact what it was and go up those 31-37 points? Or, do you think number of open installment loans is somehow figured into the equation or something?
@Anonymous wrote:I'm all about more testing with installment loan breakpoints
If you paid the new loan down to 9% and your SSL is < 9% already (I'm assuming) wouldn't your aggregate utilization return to the same scoring range now that it was prior to taking out this new loan? That being the case, don't you think your score will return to exact what it was and go up those 31-37 points? Or, do you think number of open installment loans is somehow figured into the equation or something?
Yes I am expecting the scores to increase 31 and 37 points, more or less.
Once the correct balance is reported on EX & TU, showing 8.9% instead of 89%, I may go ahead & waste some money on a second 3B report for this month, so I can test the impact of installment utilization on scores other than FICO 8. It would be a rare opportunity for me to do that.
I.e., as of today I have the mortgage scores with 89% installment utilization. It would be of great interest to me to see where they sit when the correct balance reports.
@Anonymous wrote:So it sounds like it's too late to do the test of going from > 80% to 11%... and then moving to 8.9%. The paydown to 11% has been the one talked about a fair amount in the last few weeks. Going from > 80% to 8.9% is pretty well tested, yeah?
No way I was going to do that here.
(a) I didn't like having my scores lowered 37 points.
(b) I didn't like the credit life insurance & credit disability insurance they were charging
I'm not a good test subject, because I don't like suffering.
@SouthJamaica wrote:
@Anonymous wrote:I'm all about more testing with installment loan breakpoints
If you paid the new loan down to 9% and your SSL is < 9% already (I'm assuming) wouldn't your aggregate utilization return to the same scoring range now that it was prior to taking out this new loan? That being the case, don't you think your score will return to exact what it was and go up those 31-37 points? Or, do you think number of open installment loans is somehow figured into the equation or something?
Yes I am expecting the scores to increase 31 and 37 points, more or less.
Once the correct balance is reported on EX & TU, showing 8.9% instead of 89%, I may go ahead & waste some money on a second 3B report for this month, so I can test the impact of installment utilization on scores other than FICO 8. It would be a rare opportunity for me to do that.
I.e., as of today I have the mortgage scores with 89% installment utilization. It would be of great interest to me to see where they sit when the correct balance reports.
Those are some mighty hefty score drops. I wonder if the drop is partially due to time since most recent account is too short in addition to aggregate B/L being too high. You may not get all your points back right away. Let us know what happens.
EQ stands for Equifax, TU stands for TransUnion, EX stands for Experian, FICO stands for FICO NextGen
Risk Reasons | EQ | TU | EX | FICO |
Length of time installment loans have been established | 25 | n/a | 25 | J4 |
Time since most recent account opening too short | 30 | 30 | 30 | K2 |
Proportion of loan balances to loan amounts is too high | 33 | 3 | 33 | P9 |
Length of time open installment loans have been established | n/a | n/a | 36 | J6 |
@Thomas_Thumb wrote:
@SouthJamaica wrote:
@Anonymous wrote:I'm all about more testing with installment loan breakpoints
If you paid the new loan down to 9% and your SSL is < 9% already (I'm assuming) wouldn't your aggregate utilization return to the same scoring range now that it was prior to taking out this new loan? That being the case, don't you think your score will return to exact what it was and go up those 31-37 points? Or, do you think number of open installment loans is somehow figured into the equation or something?
Yes I am expecting the scores to increase 31 and 37 points, more or less.
Once the correct balance is reported on EX & TU, showing 8.9% instead of 89%, I may go ahead & waste some money on a second 3B report for this month, so I can test the impact of installment utilization on scores other than FICO 8. It would be a rare opportunity for me to do that.
I.e., as of today I have the mortgage scores with 89% installment utilization. It would be of great interest to me to see where they sit when the correct balance reports.
Those are some mighty hefty score drops. I wonder if the drop is partially due to time since most recent account is too short in addition to aggregate B/L being too high. You may not get all your points back right away. Let us know what happens.
EQ stands for Equifax, TU stands for TransUnion, EX stands for Experian, FICO stands for FICO NextGen
Risk Reasons
EQ
TU
EX
FICO
Length of time installment loans have been established
25
n/a
25
J4
Time since most recent account opening too short
30
30
30
K2
Proportion of loan balances to loan amounts is too high
33
3
33
P9
Length of time open installment loans have been established
n/a
n/a
36
J6
The reason I stopped trying to measure the effect of things on my scores other than FICO 8 is because (a) my profile is busy and (b) I only had access to the scores other than FICO 8 on a monthly basis. But I can usually tell what's causing an effect on FICO 8 because (a) I monitor the score daily and (b) I have daily access to my updated credit reports through experian.com, equifax.com, and transunion.com. So I can usually isolate a score change, unless some other report change occurs on the same day. In this case, there was no other change on the same day, so there is no doubt that the 37 point drop on TU and the 31 point drop on EX are both attributable to the addition of the installment loan triggering 89% installment utilization.
The installment loan's impact as being a new account is a non-event, since I have a new account almost every month 
All the other 'newness' factors are likewise non-events, since they have been a constant with my profile for several years.
I believe that within a few days the new installment balance will report, and I've today captured my scores across the board with the 89% utiliization number. So this will be a rare opportunity for me to isolate the impact of the installment loan paydown on the mortgage models if I spring for a second 3B report.
BTW in case you're wondering why I mention EX & TU but not EQ, it's because for some reason the installment loan hasn't made it to my EQ report in any fashion.
@Anonymous wrote:In the SS Loan thread, it's normal for people to report score changes in the 30s and occasionally 40s. So I find your results very plausible.
When I got my auto loan, my TU FICO 8 dropped 41 points