Patsy, did your fuel economy go down? I agree with the idea of sticking with a good station when you find one. I routinely buy Mobil diesel from a car/truck stop just off the N.J. turnpike. I know their stuff is fresh. Oddly though, I don't recall seeing a cetane number on the pump. I just came back from visiting my folks in Virginia, and all the Texaco stations had "Premium Diesel" with a cetane rating of 45. When I first bought my car, I was buying my diesel locally and was getting about 25-27 mpg. After reading here about differences in diesel from one station to another, I tried this Mobil diesel. My fuel economy shot up to 29-30 mpg. The kicker is that this Mobil diesel cost less than the local stations.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member