will auto loan negatively impact my score?

[Suddenlyy]

right now my fico score, shown on my discover statement, is 754. i have 10 open credit cards, about 35k in open limits, and 1% card utilization. AAOA is just barely over a year. besides credit cards, i have no other types of loans on my CR.

What i want to make sure is, if i co sign on a 5 year auto loan, will that have any short term negative impact on my fico score? (it is an additonal ~15k debt afterall)

the reason i am asking is within the next 1-3 years, i will hopefully be getting a mortgage (with same person from the auto loan) 

i want my score to be the highest it can when i get a mortgage.. also they wouldnt double dip when calculating DTI would they? IE,supposing the car payment  is  $260/M, would they see it as $260 for each of us? ($520/m total)

[redbeard]

You will likely see a short term 5 point dip (give or take a few points) from the extra credit pull.

Depending on your file, you may see a longer term gain from a better credit mix, but if you already have an auto loan, then this probably will have little impact.

A bit of crystal ball stuff goes on beyond that, but within 6 months to a year, it should have no real impact on your score, possibly a slight improvement if you have a better mix.

No, it will only count once for total DTI.  Its 1 bill.  It will show as the same account number so even if questioned, it is easily explained.

If possible though, I recommend getting the house first, the car second, even if this means getting a used car for now till the house is taken care of in a few years.

Dan