Today, if we look at the comparative valuations of two companies, XOM is trading at a P/E of around 11, while CVX is trading at a P/E around 9. From the onset, there at least appears to be a valuation bias towards CVX. Yet, it is important to note that XOM has traded with a "normal" P/E around 15 during the last decade and a half, while CVX has been trading with a "normal" P/E around 12 over the last 15 years. Below we see that 24 analysts have come to a consensus estimated earnings growth rate of 3.2%. By turning to Zack's as a double check, one would find a similar estimate. In turn, using default estimates and an ending P/E of 15, the F.A.S.T. Graphs Estimated Earnings and Return Calculator projects a possible annualized return of about 11%. It's important to remember that this is a calculator only, but the projections appear sensible. In looking at the Estimated Earnings and Return Calculator for Chevron, we see 14 analysts reporting to S&P who come to a consensus estimated earnings growth rate of 6.8%. Once more checking the consensus reporting by Zack's we find a similar number. Thus, the higher growth rate, higher initial yield and same ending P/E leads to a possible five-year estimated annual return of about 16%. Interestingly, a P/E of around 12 for CVX still might place it slightly ahead of the assumptions made for XOM with an ending P/E of 15. In sum, I agree with Cramer in indicating Chevron presently appears to be a slightly more attractive investment than Exxon. However, that's not to say that XOM isn't worth a further look as well. After all, it's hard to discount a company that's been growing earnings by double digit growth rates and has increased its dividend for 31 straight years. For that matter, it's hard to discount a company with a baseline possible estimated total return over 10% as well. Whether your investment of choice is CVX, XOM, a different oil company or a business in a different sector altogether, the point is that investing preferences change in tandem with valuation changes. At the time of publication the author was long CVX and WAG.This article was written by an independent contributor, separate from TheStreet's regular news coverage.