We still have our 09 Cadillac DTS. It is a very nice car but the gas mileage we get is horrible. On top of that Cadillac says that premium gas should be used which ends up putting even more money in the pockets of the oil companies. We were averaging about 18 mpg between city and highway driving so before I purchased the MKZ hybrid I did a little math. Using the figure 20 mpg average for the DTS and 40 mpg for the MKZ I calculated the cost of gas for each car over 100,000 (which is about how long we usually have our cars). So, driving 100 miles in the DTS I would use 5 gallons of gas and driving 100 miles in the MKZ I would use 2.5 gallons of gas. At $3.00 a gallon I would spend $15 for the DTS and $7.50 for the MKZ per 100 miles. Over 100,000 miles I would spend $15,000 on gas for the DTS and $7,500 dollars on the MKZ. Run those same calculations at $3.50 a gallon or $4.00 a gallon.
My conclusion, why would I not buy an MKZ hybrid.