S430 guzzling more gas than usual?
Thread Starter
MBWorld Fanatic!
Joined: Aug 2005
Posts: 4,574
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From: Sugar Land, TX
BMW E39
S430 guzzling more gas than usual?
I thought I was seeing things with the fuel gauge, so I decided to take it out to the highway and just drive at a steady pace with cruise control on for about 40 minutes. Before I left, I checked the tires cold and pumped the fronts to 31 psi and rears to 33 psi.
I just got back from the drive and even at a steady 65 mph with cruise control, the highest mpg the car got was 21 mpg. I was disappointed. I remember a year ago, she would ride along at 26-29 mpg. Anyone know if its something wrong with the motor or a part or something?
I just got back from the drive and even at a steady 65 mph with cruise control, the highest mpg the car got was 21 mpg. I was disappointed. I remember a year ago, she would ride along at 26-29 mpg. Anyone know if its something wrong with the motor or a part or something?
Super Member
Joined: Nov 2005
Posts: 790
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From: West Palm Beach
2004 S500
If it were me...I would check the mileage the old fashioned way with a full tank and a refill after a run...then do the math. If nothing else has changed and you get a normal manual reading...suspect a fuel meter calibration issue or something equally as mundane. Don't loose any sleep over it. 
Thread Starter
MBWorld Fanatic!
Joined: Aug 2005
Posts: 4,574
Likes: 3
From: Sugar Land, TX
BMW E39
Originally Posted by sprink49
Don't loose any sleep over it.
I was thinking MAF sensor, would that be a possibility?
Super Member
Joined: Aug 2005
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I had my MAF meter failure a couple of weeks ago. If its that you will more than likely have your check engine light on and also a slightly rough idle. When mine was replaced a had average 26 mpg highway. The only thing, I never checked the average gas mileage before this so I cant tell you if the gas mileage improved after the service.
