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Discussion Starter · #1 ·
The acceleration is better, the idle is smoother...I don't get it. I like being full too, but a machine shouldn't care as long as it has any fuel at all. What would be causing the performance to drop when the tank gets close to empty?
 

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Discussion Starter · #3 ·
It should be quicker with less fuel, as in less weight to haul around.
Should get marginally better mpg, too.
Good to know I don't have a flawed understanding of physics. And yet, it doesn't work better. I haven't had the opportunity to log data to confirm my thoughts yet, but I swear the engine gets more gas when the tank is full.
 

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How many miles on the odo? If it's over 60K and your fuel filter is partially blocked(?), your fuel pressure might be slightly higher (pump NPSH) when the tank is full.

:beer:
 

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Good to know I don't have a flawed understanding of physics. And yet, it doesn't work better. I haven't had the opportunity to log data to confirm my thoughts yet, but I swear the engine gets more gas when the tank is full.
I can second that too...I was used to think that its psychological...I used to think its just making me feel better that I am not straining the fuel pump anymore and hence the car is running more smoothly :lol:

I too have been really curious about this since a long, long time now...
 

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full tank!

Yeah the extra weight of the fuel in the full tank will help the fuel pump to overcome an overdue filter change,decreasing as the fuel level goes down,quite simple really!Cheers Calum:thumbup:
 

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Agreed with 'lec and calum. Swap the fuel filter, if that doesn't do it, maybe your fuel pump is going... ouch.

I have a fuel pressure gauge on my car. When I replaced the fuel filter at about 80K, I gained ~3 psi of fuel pressure, IIRC (gee, that was 80K ago!).
 

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Discussion Starter · #10 ·
I've been thinking it could be the fuel filter. I'll have to get that changed when I get the rear brake lines installed, since the mech. will be in the general area anyway. (I'm lazy and I don't feel like smelling like gasoline.)
 
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