The IRS has new numbers on mileage standards that are up to just under 60 cents/mile. Clark has traditionally said that it costs you around 50 cents a mile to operate a vehicle, but now that's obviously changing.

Fuel is only a part of the cost. But we've become so myopic by only focusing on the mpg ratings. In fact, people are making emotional auto-buying decisions based on those mpg ratings.

Clark's Dash unit has added a feature that lists nearby gas stations and their prices. That goes to show our fixation on gas prices. Likewise, comparison sites like GasBuddy.com and others are booming.

But Clark encourages you to step back and think about the big picture. Even with $4/gallon gas, it's the overall cost of a vehicle that matters: Depreciation, insurance, the cost of your loan, maintenance, repairs, etc.

If you go from a gas guzzler that's paid for to a new vehicle with a 5-year loan, think about the cost of that loan every single month. Not to mention that dumping your gas guzzler will probably get you awful trade-in value.

You may need to reconsider that choice.