Fuel Tank Fill Levels
Thread Starter
MBWorld Fanatic!
Joined: Mar 2006
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From: West Virginia
2001 E320 RWD - Brilliant Silver/Ash: 100,000+
Fuel Tank Fill Levels
Hello Friends,
I have been told that to have the various fuel tank levels at, or below, 1/4 tank is hard on the fuel pump (not necessarily in our fine vehicles, but others). Is this true of the M-Bs also?
I know about the theory concerning water condensation in the tanks due to low levels, but I would welcome any comments on this issue as well.
Thanks in advance,
Musikmann
I have been told that to have the various fuel tank levels at, or below, 1/4 tank is hard on the fuel pump (not necessarily in our fine vehicles, but others). Is this true of the M-Bs also?
I know about the theory concerning water condensation in the tanks due to low levels, but I would welcome any comments on this issue as well.
Thanks in advance,
Musikmann
Senior Member
Joined: Jun 2002
Posts: 254
Likes: 3
Yes, running your tank very low is hard on the fuel pump but it's not really condensation that is the issue but it's that the fuel pump relys on the gas to cool it. The fuel pump needs to be submerged in the gasoline to keep it cool. The more time it spends unsubmerged, the hotter it runs which leads to a shorter service life.
Super Member
Joined: Apr 2005
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From: oregon
2011 C300
Originally Posted by Petmerctech
Yes, running your tank very low is hard on the fuel pump but it's not really condensation that is the issue but it's that the fuel pump relys on the gas to cool it. The fuel pump needs to be submerged in the gasoline to keep it cool. The more time it spends unsubmerged, the hotter it runs which leads to a shorter service life.
Super Member
Joined: Jul 2005
Posts: 717
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From: Manassas, VA, USA
2011 VW cc, 2004 ML350
Well, the tank pickup is always on the bottom of the tank no matter how much fuel is present. They have a screen on them to keep large debris form getting into and fouling the pump. Small particulate matter is then trapped by the filter before entering the rest of the fuel system. The cooling issue mentioned above is the primary issue.
Thread Starter
MBWorld Fanatic!
Joined: Mar 2006
Posts: 1,627
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From: West Virginia
2001 E320 RWD - Brilliant Silver/Ash: 100,000+
How low?
Originally Posted by Jayhawk
So exactly how low should I go so as not to hurt the pump? Above 1/8, 1/4, 1/3 of a tank? Any variables that affect safe minimums?
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Joined: Sep 2005
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From: Lawrence, KS (USA)
S500/W220/2000
Originally Posted by Musikmann
Why go low at all? Unless you have to drive several hundred miles without passing a gas station, refill it at 1/2 tank. Just a thought...
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Thread Starter
MBWorld Fanatic!
Joined: Mar 2006
Posts: 1,627
Likes: 5
From: West Virginia
2001 E320 RWD - Brilliant Silver/Ash: 100,000+
Petmerctech
Originally Posted by Petmerctech
I would say 1/4 of a tank would be a reasonable limit to refuel.
Thanks my friend
