[cwerdna]

Sorry to hear about your troubles but the OP's mileage drop isn't necessarily that huge. See http://www.cruzetalk.com/forum/27-f...eage-no-its-your-gallonage-really-counts.html.

Even if you car were having no trouble, you'd have a mileage drop in the winter. See http://www.cruzetalk.com/forum/27-fuel-economy/3459-ok-whats-deal-major-drop-mpg-2.html#post44246 for why.

 

[cwerdna]

I disagree; a reduction of 15% is pretty substantial. Also, I'd be more concerned about the mpg drop being a symptom a larger problem as the OP and some others have suggested.

It sounds large from a mpg point of view, but from a gallonage POV, the delta after 100 miles of driving would be ~0.38 gallons.

If you had a car that got 20 mpg and it dropped to 18.5 mpg, would you notice or make a big deal out if it? After 100 miles, the delta between those is ~0.41 gallons.

Agree that it could be the symptom of a larger issue.