Home loan pre-approval; Is refinancing an auto loan to lower dti a smart move?

[Anonymous]

I got my median score up to 668 which qualifies me for a USDA home loan up to $225K according to my potential lender. The homes I am looking at are around $255K which is on the low end in my area of Colorado. I have an auto loan of $13K which is my only debt owed but I pay $348 monthly at 10% interest (Credit was much lower when I applied for the loan). If I were to refinance my auto loan at around 4% for 60 months that would lower my monthly payment by around $100 per month. Is this a bad idea to do when looking to close on a house within the next 6 months?

[Anonymous]

How much was the auto loan originally for? 

Refinancing could cause your EX mortgage score to go down, but if the EX score is already the lowest of your three scores that is no problem.  We'll be able to guess better how much your EX score might go down when you tell us the amount of the original loan.

EQ and TU mortgage scores would be affected much less, except as the change in AAoA affected them and possibly Age of Youngest Account and an inquiry.

And is this auto loan your only open installment loan?

The advantage to the refinance is that it would affect your DTI by lowering the monthly payment.

There seem like pros and cons and there's no way to begin to weigh them against each other without knowing a lot more.  E.g. is your EX score your lowest mortgage score?  Do you need an improvement to DTI?  What was the original amount of the car loan?  What is your AAoA now and what would it be after the re-fi?  What is the age of your youngest account right now?  Etc.