I know a lot of you guys now run fuel pressure gauges so I’m curious what kind of drop in pressure you are seeing as the filters get dirty and if anyone is going beyond the typical 10k mile recommendation.

My data point. Was approaching 10k miles on my filters. Was considering going to 15k. Hadn’t plugged in the Edge cts for a while as I’m afraid someone will steal it. Hot idle pressure was a nice steady 57-58. A somewhat brisk acceleration around 10psi of boost it was down to 50. Full pedal it was setting off my alarm and getting down to almost 45. So that prompted a filter change. Now mild acceleration is around 55psi and full pedal is 50-51. Idle is still 57-58.

Filters were stock Racor. Truck has a blue spring that is about 2 years old.

Filters didn’t look bad but I’m sure it’s nigh impossible to see 10 micron particles.

 

10psi difference from idle to WOT is normal (stock injectors) . As long as your FP stays above 45psi, everything is ok.
I change my filters every 15-20K

 

My 6.0 machines all run 60+ psi and are all instrumented.

Run strictly Moto oil and fuel filters (for more reasons than I have time to write here).

 

45 psig minimum is what Ford published.

I tend to want 50 psi minimum, with 60 psi being "typical".

You never know how accurate the pressure measurement system is and we will never be watching the gauge frequently enough to catch all the dips, even if the instrumentation has a fast update rate.

 

You meanr 50-60 at WOT?

I meant 45psi at WOT = 55 psi cruising .
sorry for confusion.

 

I do mean 50 minimum at WOT. IMO the gauge could easily be off by 5 psi, so I like to see 50 at the lowest.

Just my conservatism.

 

Mine idles at 57-58 psi and doesn't go below 53 psi at WOT.

 

What kind of degradation do you guys see as the filters get older? That was the main purpose of my thread...

 

Call me abnormal, but with the dual readout single pod I had on the A-pillar saved me three or four times.
Once towing through CT I observed coolant pressure drop from the at the time 12psi to 4 then 0. I pulled over and found a cracked Y-pipe.
Towing again in TN while pulling away from a traffic light at above med. throttle fuel pressure dropped to 30. I let off and got back on it and at WOT it was going to 0. I milked it until I could stop using only light throttle until I could pull it apart. It was a bad regulator seal. This has happened actually 2 or 3 times throughout the life I owned my dually. It's been a minute but if I remember right, the gauge is what told me my pump wasn't keeping up either causing me to replace it. This is why I recommend a dual gauge, fuel and coolant pressures, on the A-pillar where you easily view it subconsciously.

Top (amber, color of fuel): Fuel pressure
Bottom (red, color of Rotella ELC): Coolant pressure


For the fuel filters, I changed it every other oil change. The gauge never was effected. Maybe I got lucky getting clean fuel.

 

I see no change in pressure from new to 10k mile change over the last 100k miles.

 

Totally agree - my fuel pressure gauge caught my fuel pump failure AND a failing (intermittent) fuel pump relay.

My point in my earlier post was to bump the minimum pressure value up a bit, just to be safe.

I haven't ever really benefited from my coolant pressure gauge, but I have one and I see how it could be a big help. I have only had a coolant leak once and it was very small.

I also have not seen any pressure impact over the life of the fuel filters.

 

I haven’t seen degradation over the 10k mile interval. 57-58 at idle, still that at around 10psi boost, wide open throttle will drop below 50psi if I hold it to the floor for a bit but I’m tuned