Investors interested in Financial - Consumer Loans stocks are likely familiar with Santander Consumer (SC) and Sallie Mae (SLM). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The Zacks Rank favors stocks with strong earnings estimate revision trends, and our Style Scores highlight companies with specific traits.Santander Consumer has a Zacks Rank of #2 (Buy), while Sallie Mae has a Zacks Rank of #3 (Hold) right now. Investors should feel comfortable knowing that SC likely has seen a stronger improvement to its earnings outlook than SLM has recently. But this is just one factor that value investors are interested in.Value investors analyze a variety of traditional, tried-and-true metrics to help find companies that they believe are undervalued at their current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.SC currently has a forward P/E ratio of 6.95, while SLM has a forward P/E of 7.52. We also note that SC has a PEG ratio of 0.37. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. SLM currently has a PEG ratio of 0.39.Another notable valuation metric for SC is its P/B ratio of 0.96. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. For comparison, SLM has a P/B of 1.64.Based on these metrics and many more, SC holds a Value grade of A, while SLM has a Value grade of C.SC has seen stronger estimate revision activity and sports more attractive valuation metrics than SLM, so it seems like value investors will conclude that SC is the superior option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Santander Consumer USA Holdings Inc. (SC): Free Stock Analysis Report SLM Corporation (SLM): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research