Does your W124 nozzle automatically cut out at 18.5 gal as stated in the manual?

[JJB236]

My 91 300E has 188,000 miles, and the car used to go up to about 270 - 300 miles miles on a full tank. History of the car: A $2,000 valve job was done on the car five months ago in Dec 05. Lately, I noticed that on a full tank, it only does about 200 - 210 miles.

I think such large difference in MPG comes from the difference in the quantity of gas at full tank.

According to the manual, only premium unleaded is recommended. And the fuel tank capacity is at 70 l (18.5 U.S. gal), which includes 9.0 l (2.4 U.S. gal). It also says not to overfill. It says "Only fill fuel tank until the filler nozzle unit cuts out." I think the nozzle unit cutting out varies significantly each time.

At how many gallons does your W124 nozzle cut out? I just looked at the receipt which says 14.756 gal which is far less than the capacity of 18.5. Check your gas receipts.

[Uboater]

I always thought the tank has a huge reserve , 2-3 + gallons remaining when the low light comes on. I notice any slope at the station will reduce my fill amount. You could pump and burp another 2 gallons in I bet .

[vili1982]

I put a new Oxygen Sensor, I seem to be getting higher gas mialage.

[JJB236]

Originally Posted by vili1982

I put a new Oxygen Sensor, I seem to be getting higher gas mialage.

Hmmm a new oxygen sensor... My mechanic was telling me that the "check engine light" came on because it needs a new oxygen sensor. I am getting one next week.

At how many gallons does your car top off automatically?

[neanderthal]

dependes on how much gas is left in the tank.

depends on how well maintained the nozzles are at the gas station.

depends on incline

probably depends on how high the altitude is.


i generally fill up my tank when the light has been on for a day. that doesnt mean ive been driving the whole day, but doing my normal routine. about 45 miles a day.


i get anywhere from 15 to near 18 gallons. i have never actually filled 18 gallons although ive tried over and over again. ive come close a few times.

i do know that the reserve light first comes on, intermittently, when there is about 3 gallons left, and stays on when there is about 2 gallons left.