Hello Drivers,

I own a 1999 ML-320 with 135,000 miles. I'm the original owner. Since the day I bought this truck I have always documented my fuel purchases. I have an excel spreedsheet from last 10 years which shows day, price, location, gallons, price p/gallon etc of all my fuel purchases.

I lived in Texas for a year, Virginia for 4 and a half and Florida for 5. All this time I could look at my spreedsheet and tell you that on a tank of petrol I can drive 320-340 miles.

Today, however, things are different. All of a sudden during the last two tankings my mileage has gone to 374 and 391 miles respectively.

Is their a theory for what is going on?

Thank You!!!

 

I would suggest checking your transfer case or 4x4 option because drastic gas consumption decrease like this could happen by disabling (disconnecting) driveshaft to front differecial. Also intake tube disconnection from throttle body or higher octane gas.
I would be happy if it would happen to mine but so far about 320 miles per refill (15-16 gallons).
Bernard

 

I could live with this problem.