Better mileage ?

[Jeremiah]

Re: Mileage

Originally posted by W. A. Derby



.

Not only do I drain the filter every tank I also add a fuel conditioner that raises the centain & absorbs moisture. Although according to the column in issue 39 a .

I don't think it's condensation in a truck's tank as much as it is water picked up at the pump. It comes from tanks that aren't pumped from often enough and also from retailers that buy from non-reliable distributors. Any place that services lots of trucks should be O. K.

 

[Iguide]

Re: Re: Mileage

Originally posted by Jeremiah

I don't think it's condensation in a truck's tank as much as it is water picked up at the pump. It comes from tanks that aren't pumped from often enough and also from retailers that buy from non-reliable distributors. Any place that services lots of trucks should be O. K.

There are only two places to buy diesel & they both sell to truckers. Littleton is the largest town for 60 mi. These places sell all the fuel here. So I think that condensation is somewhat of a factor. I can't really come up with other reasons. I will differ my limited knowledge to those { you } who know more & are more experienced. I just don't know what else could help contribute.

 

[Jeremiah]

Re: Re: Re: Mileage

Originally posted by W. A. Derby

There are only two places to buy diesel & they both sell to truckers. Littleton is the largest town for 60 mi. These places sell all the fuel here. So I think that condensation is somewhat of a factor. I can't really come up with other reasons. I will differ my limited knowledge to those { you } who know more & are more experienced. I just don't know what else could help contribute.

If condensation is the problem, it might be alleviated by keeping the tank full or mostly full. Condensation is the result of cold fuel and warm, moist ambient air. It's more of a problem w/metal tanks, which I don't believe our trucks have.

 

[Iguide]

Re: Re: Re: Re: Mileage

Originally posted by Jeremiah

If condensation is the problem, it might be alleviated by keeping the tank full or mostly full. Condensation is the result of cold fuel and warm, moist ambient air. It's more of a problem w/metal tanks, which I don't believe our trucks have.

\



You are correct. We have a type of plastic , I think. Anyway I've crawled under mine & it is NOT mettle. Your statement about tank level & condensation I believe is correct. I have a {bad} habit of seeing how far I can go on a tank before refueling. Guess I like to live dangerously. . & I'm sure I'll not get myself to do it differently, like I should. It would make to much sense.

 

[Dean Upson]

I don't think that condensation is near the problem that it was in the past when we had metal tanks. Years ago we always topped of the metal tanks on heavy equipment before shutting down.



Dean

 

[Jeremiah]

Re: Re: Re: Re: Re: Mileage

Originally posted by W. A. Derby

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You are correct. We have a type of plastic , I think. Anyway I've crawled under mine & it is NOT mettle. Your statement about tank level & condensation I believe is correct. I have a {bad} habit of seeing how far I can go on a tank before refueling. Guess I like to live dangerously. . & I'm sure I'll not get myself to do it differently, like I should. It would make to much sense.

I do the same thing (drive right up to the last gallon ... ). Being an old pilot, I remember that everything becomes rate once the cockpit door closes. Rate of climb, fuel burn per hour, etc. That can make a difference when you're going somewhere and need to know precisely how much fuel it will take to get there. It can mean the difference in not having to stop and gas up.

 

[ray1933]

Better mileage

Was it on this thread that I read about 60 front & 50 rear tire pressure for better mileage?? If so was the truck a 1/2 , 3/4 or one ton. Just checked mine and they have 65 both front and rear.

 

[Jeremiah]

Re: Better mileage

Originally posted by Ray

Was it on this thread that I read about 60 front & 50 rear tire pressure for better mileage?? If so was the truck a 1/2 , 3/4 or one ton. Just checked mine and they have 65 both front and rear.

Probably this thread ... I mentioned it way back when. I've been running 60/50 in my 3500 SWR for 19,000 miles and getting as much as 21. 8 mpg. I rotate my tires every 5,000 miles and am now noticing more wear (down to 8/32) in the center part of the tread. The outside tread is still 11/32, which tells me not enough tread is on the road (i. e. , I am running too much air). I've backed off 10 lbs all around and expect the tread to wear more evenly, but I also expect the mileage to drop a bit. It's a trade-off.



But I have noticed that when I run max pressure (use the owner's manual for a guide) for hauling heavy loads in the bed, the truck gets squirrelly when it's empty.

 

[Bertram65]

2000 miles so far, 17. 5, 16. 9, 16. 1 and 15. 9 in that order for the 4 tanks of fuel. I read in one of the manuals that came with the truck that 50 PSI in the front and 40 PSI in the rear for unloaded not hauling, which is what I have been doing. Most of my driving is around town so I figure with the 48RE and 4. 10s it's not too bad, when I run on the highway I usually run about 72MPH which is about 2200 RPM.

 

[Jeremiah]

Originally posted by Bertram65

2000 miles so far, 17. 5, 16. 9, 16. 1 and 15. 9 in that order for the 4 tanks of fuel. I read in one of the manuals that came with the truck that 50 PSI in the front and 40 PSI in the rear for unloaded not hauling, which is what I have been doing. Most of my driving is around town so I figure with the 48RE and 4. 10s it's not too bad, when I run on the highway I usually run about 72MPH which is about 2200 RPM.

OK, I got it, now that I see what you're driving. 4. 10 rears, duallies, automatic trannies, big tires, heavy feet, etc. , all compete for the low mileage award of the year. I have the 3. 73, which helps out enormously. I wish they hadn't done away with the 3. 55 because most of my miles are solo. At least they could have given us a third option.



With my 3. 73, 1800 or 1900 is the most economical rpm. If I run it up to 2200 the mileage will fall. Can't say about the 4:10, never had one of those, although I know they are pullin' MOTHERS!

 

[Dean Upson]

Can't say about the 4:10, never had one of those, although I know they are pullin' MOTHERS!

They are, indeed .



Dean

 

[Jeremiah]

Originally posted by Dean Upson

They are, indeed .



Dean

I'll be in your state beginning Aug. 14. I expect to see a series of black peel marks - make that duallie peel marks - about 20 yards apart left by U-Kno-Who on every highway!

 

[Jeremiah]

Originally posted by Jeremiah

OK, I got it, now that I see what you're driving. 4. 10 rears, duallies, automatic trannies, big tires, heavy feet, etc. , all compete for the low mileage award of the year. I have the 3. 73, which helps out enormously. I wish they hadn't done away with the 3. 55 because most of my miles are solo. At least they could have given us a third option.



With my 3. 73, 1800 or 1900 is the most economical rpm. If I run it up to 2200 the mileage will fall. Can't say about the 4:10, never had one of those, although I know they are pullin' MOTHERS!

OK, I have an even better idea of mileage now. I drove to Omaha (645 miles) at a s-t-e-a-d-y 62-63 mph (a-a-r-g!) or 1900 rpm and got 24. 4 mpg. Not baaaad! Keep in mind it's downhill all the way.



On the way back I kicked it in the butt (70-75 mph and 2200 rpm) and got 18. 2 (double a-a-a-r-g!) mpg. 'Course it's uphill too, but only slightly. Maybe there was a headwind ...

 

[lrausch]

03 MPG

FYI



Here is my story.



I just got back from a 2800 mile trip from Chicago to Palm Beach and back minimal load driver only and 200lbs of luggage. My truck is an 03 HO with 6speed 3. 73 and 44psi air in all four tires, otherwise my truck is all factory setup with about 10K. My worst mileage was 17. 3 MPG and my my best 19. 2 MPG, and my speed was between 65 and 90MPH. However I found if you want to maximize your mileage the best approach is to keep the RPMs between 1700 and 1900, which would put me around 60+ MPH a little bit to slow, but if you don't mind traveling at or slightly below the speed limit 20+MPH is possible as long as you use progressive shifting.



Hope this helps



Regards,



Laszlo

 

[Jeremiah]

Re: 03 MPG

Originally posted by lrausch

FYI



Here is my story.



I just got back from a 2800 mile trip from Chicago to Palm Beach and back minimal load driver only and 200lbs of luggage. My truck is an 03 HO with 6speed 3. 73 and 44psi air in all four tires, otherwise my truck is all factory setup with about 10K. My worst mileage was 17. 3 MPG and my my best 19. 2 MPG, and my speed was between 65 and 90MPH. However I found if you want to maximize your mileage the best approach is to keep the RPMs between 1700 and 1900, which would put me around 60+ MPH a little bit to slow, but if you don't mind traveling at or slightly below the speed limit 20+MPH is possible as long as you use progressive shifting.



Hope this helps



Regards,



Laszlo

Yup, that works, Laszlo. Most people drive according to the speedo, when they really should let the tachometer govern things. Wanna fly? Drive at 2200 rpm and fergit the mpg. Wanna get good mileage? Keep 'er at 1800 or 1900 and watch the mpgs creep into the mid-20's. Cummins engines can handle it either way, once they get broken in. I wouldn't want to baby the engines on break-in though. Better to haul or pull, which is what the engines were designed to do. If that's not an option, keep the rpms up and don't lug the engine. As a Cummins rep told me, "You can't hurt these engines because they are de-rated. You can run 'em wide open all day long and it won't hurt 'em. They are built to run wide open. " 'Course, if you do that, you won't get good mpgs either. Hee!

 

[Kilby]

So if 1800-1900 rpm is optimal for better mpg, and I want to travel at 80 mph which is around 2500 rpm for me, what if I was to install a Gear Venders OD unit dropping my rpm to around 1950 rpm at 80mph? You think I'll get better mileage at that speed?

 

[MMeier]

I don't see why not !!

 

[Kilby]

Well that's a good thing because I have one being installed in a couple of days. heh heh!

 

[Jeremiah]

Originally posted by Kilby

So if 1800-1900 rpm is optimal for better mpg, and I want to travel at 80 mph which is around 2500 rpm for me, what if I was to install a Gear Venders OD unit dropping my rpm to around 1950 rpm at 80mph? You think I'll get better mileage at that speed?

Yes, you would get better mileage but it could come at a price. I was thinking along those same lines once and contacted a local shop that installs GV over/under units. They said the drive shaft has to be shortened, and because the unit weighs more than the shaft, a bracket has to be fitted to hold it up. It's possible it might not line up like it should. The end result of this would be vibration.



Bottom line, a safer route to follow would be taller tires. That's what I am going to do when the OEs wear out.

 

[Kilby]

Taller tires aren't going to give the rpm reduction that I want but I will be getting taller tires anyhow.



I spoke with GV directly and they assured that you do not need an extra crossmember to support the weight of their unit. Since the rear DS is a two piece design, all they need to worry about is the front half of the DS and it's operating angles. I'm sure they've installed enough of these units to know how to correct the angles. I hope anyhow.



Reguardless, I'll let ya know in a couple of days how it all works.