you will have to ask that question to each lender you are interested in. And then, as mentioned above, they might not use the FICO score, but their own version. Each lender is different and you will have to ask them. The answer is above, you just need to learn how to interprete it.
Yeah, different lenders pull different credit bureaus. But two of the best lenders for low rate on auto loans are Penfed and DCU credit unions. They both use Equifax, and as Penfed gives you a free EQ Fico 9 score and DCU gives you a free EQ Fico 5 score I assume that's the score they use for auto loans.
I have an discover card that gives me my TU Score monthly and also found that the discover scoreboard gives you your Experian score. Are those scores accurate?
Yes, they are accurate FICO 8 scores. TU FICO 8 and EX FICO 8.
Whether or not your potential auto loan provider will use either of the above scores is questionable. Your best bet is to speak with the potential auto loan lender and simply ask them what score/model they use for loan consideration. Depending on what they tell you, there may be a source for that score. Maybe not. MyFICO here provides just about every FICO score there is to my knowledge for about $30.