Will co-signing with my 700+ credit score get us a better auto loan rate?

Does co-signing provide a meaningful benefit when both individuals have credit scores in the high 700s?

I plan to acquire a new car next year, and my boyfriend intends to secure the loan to diversify his credit history. Would adding my name to the loan application improve our interest rate, or would the impact be negligible?

If the benefit is minimal, I will likely continue utilizing zero-percent financing offers. However, if it proves advantageous, I should probably refrain from that approach as the time,draws nearer.

(Yes, this is for a new car. Correct, we are not married. No, I will not reconsider based on advice against it. The vehicle is a personal reward for diligent work, and we share an interest in automobiles. This shared interest in cars is one reason we are not married, as we have directed funds toward this and other pursuits, while maintaining a relationship of just over six years.)

Since it's your car, not his, you should be on the loan as well this protects you if something happens to him, so the bank can't reclaim the car during a tough time. It would also help diversify your credit mix. If you're both already scoring in the 700s, cosigning likely won't lower the interest rate much. Overall, I'd say it is in your best interest to cosign on the loan for your own car.

Oh, my husband and I were both on the loan and the title for my car. It actually worked out perfectly and wasn’t strange at all. And get this my name on everything was still my maiden name.

Co signing differs from a joint loan. Only co sign if the primary borrower cannot qualify alone. You agree to pay if they default. This often applies to parent child loans. Joint applicants might secure a better rate if one has stronger credit. Many lenders limit co signer loans. For example, my bank caps auto loans with a co signer at $30,000.

Go ahead if you want to. Just keep,in mind, if you're sharing car insurance, it'll need to be a joint policy. If one person has more issues on their driving record, that could mean higher premiums so the other might end up paying more too.
I added my daughter's fiancé to my car insurance along with my daughter. He switches between driving her car and his own, and I didn't want either of them to be without coverage. They chip in for their portion each month.