Here's the scenario: We are 2 individuals with decent (high 700/low 800) credit scores. A handful of credit cards between us, some with 10+ years of history, which we use regularly for pretty much all purchases and pay off on time. One of us had a small (~$10k) educational loan, paid off about 5 years ago.
We do not own a house, so have never had to take out a mortgage. We have also never used a loan to purchase a car as we've generally stuck with $2-3k used cars from craigslist or family members looking to unload their vehicles. So aside from the one educational loan, there is nothing in our history to suggest we can chip away at a single loan consistently over time.
Right now we are looking at buying a (sensible, compact, used, to be used for driving non-walk/bikeable distances only) car for around $7k. We have enough cash on hand to pay for it outright, but we could also get a 72 month loan at 2.24%. My husband suggested maybe it would be a good idea to take out the loan, to "improve our credit scores", plus if the rate is suitably low it makes more sense to have money available to throw at the stock market (2.24% seems to be getting into the "suitably low" territory). There is a moderate chance we will want to buy a house within the next 5 years. While I have no doubt we could get approved for pretty much any amount of mortgage we would conceivably want, I would certainly be willing to pay a bit in interest on a car loan if it meant tens of thousands in savings on mortgage interest. And this loan is not very large relative to our net worth--we would certainly have the means to pay the balance off in full at any time if we decided it was too much hassle to keep track of a monthly payment.
I guess my question is, given that we already have good credit numbers, just how much is the presence of a car loan (plus evidence of ability to pay it off over time) really going to improve the eventual interest rate we might be offered on a mortgage? Some internet searching I have looked at suggests you need a score of 760 or better to be offered a really good rate, but we are both quite comfortably over that cutoff. Is there really a big difference between a score of, say, 810 and 820?
