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Lost fuel economy switching to synthetic engine oil?

turbovanman

turbovanman

I has boost, :O)
Messages
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Location
Abbotsford
Ok, I've gone thru 3 tanks with the new setup, 17/19 then 20 mpg, switched to Rotella 5w40 and filled up, lost 5 MPG? WTF?????????? :mad2: :confused: I've noticed a tad more power and I can see my tailpipe and its not blowing out mass clouds of smoke.

It also starts harder when cold, before, cycle glow plugs and vroom, now, it stumbles then catch's??????? Any idea's? Very strange indeed.
 
Very strange. Did you do anything else when you changed the oil? I always change the fuel filter when I change the oil. Is there a possibility that you bumped something?
 
Not sure on the fuel, same gas station since November. All I did was change the oil, that's it, nothing else was touched, :confused:
 
Something makes no sense. It would almost have to be fuel if nothing else changed. How is the weather in Washington these days?
Open the drain and run a quart or so of fuel into a container. I use a gallon glass pickle jar. Let it sit about a half hour or so and inspect for water. Do the lift pump test while you're at it. Crack the drain with the engine running if it dies your lift pump isn't running.
 
The fuel may have been blended down from a #2 gradually to #1, which may be what you got this time.
 
jrsavoie said:
Something makes no sense. It would almost have to be fuel if nothing else changed. How is the weather in Washington these days?
Open the drain and run a quart or so of fuel into a container. I use a gallon glass pickle jar. Let it sit about a half hour or so and inspect for water. Do the lift pump test while you're at it. Crack the drain with the engine running if it dies your lift pump isn't running.
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I don't have a lift pump and the weather is actually warmer, hence why I probably got 20 the last tank, no idling to warm it up. I am in Abbotsford, next to the Washington border, :thumbsup:

I'll do that if the next tank sucks, have to take off my dog house, PITA, :mad2:


NVW said:
The fuel may have been blended down from a #2 gradually to #1, which may be what you got this time.
Click to expand...

Its possible, its just really, really weird.
 
Can a person simply put a sample of the diesel in a small glass jar w/ appropriate thermometer in it. Then put in freezer & check on short intervals to see what temp it clouds at?

I could imagine the actual cloud point test the fuel companies do, being somewhat like that, except in a certain specifically designed/sized container for the diesel, and maybe some kind of light absorbance/transmittance instrument to take a person's subjectivity out of the test.

Hard to see the syn engine oil having impacted mileage anywhere near that significantly - much less making it worse. I can say in similar outdoor early Fall temps, w/ engine oil temps up to 160-170 F, 15W-40 dino carried ~ 4-5 psi higher oil pressure than 5W-40 Mobil 1. Guess that's just related to overall viscosity differences btwn the dino & synthetic at 160-170 F oil temps.
 
turbovanman said:
I just call it a fuel pump, so yes, I have a "lift" pump then. :eek:ut::smilielol5:
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The importance that distingushed the two is that a Lift Pump "helps" fuel get to the IP. Most IP's can draw there own fuel. Even a DB2 can pull it's own fuel although it will not run good. A fuel pump Supplies fuel and is norammly associated to a gasser(yuk) that cannot draw it's own fuel. That's why the terminolgy is important so for you to say you "have no lift pump" raises questions . See my point ?
If you really wanna get historical, I believe the term lift pump came about because the fuel tanks on HD trucks are mounted low . ON Detriot 2 strokes it was referred to as a transfer pump.
 
Acesneights1 said:
The importance that distingushed the two is that a Lift Pump "helps" fuel get to the IP. Most IP's can draw there own fuel. Even a DB2 can pull it's own fuel although it will not run good. A fuel pump Supplies fuel and is norammly associated to a gasser(yuk) that cannot draw it's own fuel. That's why the terminolgy is important so for you to say you "have no lift pump" raises questions . See my point ?
If you really wanna get historical, I believe the term lift pump came about because the fuel tanks on HD trucks are mounted low . ON Detriot 2 strokes it was referred to as a transfer pump.
Click to expand...

To me, its just a fuel pump, as that what it does, just like on V8 carbed gassers, so yeah, you call it lift pump, I call it fuel pump. Like colour-color, cheque-check, ):h
 
Thought I'd update, after saying it wasn't smoking, I started noticing it was, a light blue/white haze and lots of it??????? it would come and go, also remember for that tank, I filled up at Chevron, talked to them the other day, no complaints.

Anyhow, 250K into the new tank of fuel, it stopped smoking and I noticed more power and mileage is back on par so I guess I'll chalk it up to a bad tank of fuel??????:mad2:
 
turbovanman said:
Anyhow, 250K into the new tank of fuel, it stopped smoking and I noticed more power and mileage is back on par so I guess I'll chalk it up to a bad tank of fuel??????:mad2:
Click to expand...
Wow! You're getting 250K miles on one tank of fuel and you are complaining? I'm lucky if I get 500 miles on one tank full. :confused:


















Just givin' ya a hard time! :D

I'm glad you got the fuel problem resolved.
 
Hahaha, thanks.

I average 750km's to a 25 gallons, if I am nice, maybe 800. I haven't done any extended highway trips yet so I don't know if I can get more out of it.
 
i didn't have a clue where you were so I had to ask. you make about the same as I did before the tranny change. I haven't got a clue what it is now. I know it went up though.:thumbsup:
 
just a number said:
i didn't have a clue where you were so I had to ask. you make about the same as I did before the tranny change. I haven't got a clue what it is now. I know it went up though.:thumbsup:
Click to expand...

Nice. I am changing the gear ratio soon so hopefully it won't affect it too much, :mad2:
 
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