You may actually LOSE points because your credit mix will change.
Not enough to worry about tho.
I predict a slight score bump because you still have an installment in play for the mix.
The previous FICO Admin had mentioned once that paying off a credit account will never impact your mix, regardless of being opened or closed. So, according to him, your mix wouldn't change even if that was the last and only installment reporting. Personally I had doubts, but you never know. I paid off my last installment and pulled my 2 FICOs the day before and the day after it reported to see the change. EQ increased by 7 and TU decreased by 5. I understand the increase due to an added $0 balance, but I couldn't figure out why TU decreased and always assumed it was due to an impact on mix. The pos/neg reasons also changed up.
Hmm. It may be a ymmv case.
Last year, we refinanced DW's car...out of her name, and into mine.
Now, one of her "negative" marks is not having an installment loan...
Personally with 800 left on Auto Loan most likely you have less then 10 months to pay. So that loan will not impact your DTI.
If you have credit card debt, that is where I would apply the extra payments to for a score boost. If you have no credit card debt, then you need to figure out what negative accounts you have and see what you can do to improve them.
Paying off a 800 installment loan will have very little impact if any impact at all in your scores.