fuel economy - 1999 - 7.3L Power Stroke Diesel
#31
09-06-2007, 06:22 PM
#32
09-06-2007, 07:17 PM
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#33
09-06-2007, 08:59 PM
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Originally Posted by F250_
Danny.... you got me thinking.....
The ULSD is something I haven't thought about in my recent weeks of feeling like I'm going crazy.
You see, I recently changed my oil (changed brand, but stayed with a 5w40 synthetic), and switched over to Stanadyne's Performance Formula where I was using Diesel Kleen. I also found my 6637 a little loose and tightened it back down quite tightly (had only been loose for a couple of days).
Here's the thing... ever since those changes, my mileage has dropped about 1-1.5 mpg for city, mix, and highway driving. I've been going nuts on this. I first thought it was because I of the change from DK to SPF, and am still not sure about that yet (I want to run the SPF at several dosage rates and see if there's a change, and also switch abck to the DK for a double-check as well).
Well, this past weekend, I even pulled and cleaned my EBPV sensor and tubing (and bracket fitting) this weekend, but no change yet. I've upped my Stanadyne slightly... no change yet.
It just might be that my station has finally switched over to the ULSD (I always use the same station and the same pump). I have to ask about this the next time I fill up (tomorrow evening).
Thanks for mentioning the ULSD thing, Danny.
The ULSD is something I haven't thought about in my recent weeks of feeling like I'm going crazy.
You see, I recently changed my oil (changed brand, but stayed with a 5w40 synthetic), and switched over to Stanadyne's Performance Formula where I was using Diesel Kleen. I also found my 6637 a little loose and tightened it back down quite tightly (had only been loose for a couple of days).
Here's the thing... ever since those changes, my mileage has dropped about 1-1.5 mpg for city, mix, and highway driving. I've been going nuts on this. I first thought it was because I of the change from DK to SPF, and am still not sure about that yet (I want to run the SPF at several dosage rates and see if there's a change, and also switch abck to the DK for a double-check as well).
Well, this past weekend, I even pulled and cleaned my EBPV sensor and tubing (and bracket fitting) this weekend, but no change yet. I've upped my Stanadyne slightly... no change yet.
It just might be that my station has finally switched over to the ULSD (I always use the same station and the same pump). I have to ask about this the next time I fill up (tomorrow evening).
Thanks for mentioning the ULSD thing, Danny.
#34
09-09-2007, 08:05 PM
Well, that's good to know. I'm running 285 Michelins on my 01 CC PSD 4WD and have never taken tire additional circumference into consideration for mileage. Didn't think it would make that much difference.
Thanks for the heads up.
Thanks for the heads up.
Originally Posted by JIM ROLAND
Just curious, does everyone take tire size into consideration? My mileage is not nearly as good as some of these reports. My truck is a pure stock 2000, super duty, 7.3, crew cab, 4x4, automatic, except for the fact that I have 285's instead of the stock 265 tires. I went to the Michelin website soon after purchasing the truck and got some information about the difference in the circumference of the two tire sizes. Long story short, it turns out that for every 20 miles traveled on the odometer I need to add 1 mile before calculating the mileage. I usually average about 12 to 13 around town and 21 to 22 on the highway. I towed about 3500 lbs. for 4 hours recently and got only a little over 8 mpg. I do not know what rear end ratio I have. I have gotten as high as 26 mpg in very cold weather on the interstate. Thanks in advance for all responses!
#35
09-09-2007, 08:41 PM
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#36
09-09-2007, 08:56 PM
When you say pulling 22,000, that the tow vehicle and trailer, yes? (sorry for the stupid question...newbie, you know)
Originally Posted by powerstrokinsmokin
I have a 99 f-350 with auto trans, 4" exhaust, 6 pos chip with k&n intake, stage two injectors, 3.73 gears and i can get about 16.2 mpg empty. pulling 22,000 i get about 11-11.5 going 70 mph. turns like 2050 rpms.
#37
09-09-2007, 09:16 PM
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#38
09-10-2007, 10:55 AM
Thanks for the details, Brandon, but that really doesn't encourage me, especially given the shift in mileage, except I guess it may really mean that I can find some other culprit and regain my losses. The pumps I'm filling up at are all still labelled LSD... don't know why - it's a BP truck stop that has very heavy traffic.
Oh well.
Oh well.
#39
09-10-2007, 11:09 AM
Hotshot
Dont know how many might have this toy, but you can use your GPS normally to find out how fast you are actually going. then use that for figureing out your GPM. Say you set the Cruise at 70, GPS says you are doing 73. Divide the 70 into 73, you end up with 1.04. Multiply that by you trip odometer, then divide your gallons into that.
#40
10-22-2008, 03:04 PM
#41
10-22-2008, 03:23 PM
Tire size calculator go here and it will give you a percentage difference and multiply your millage by that. 1.037 if your old tire size was 265 75 16. if so your getting 14.518mpg. if they are right didnt check any other sites to confirm.
#42
10-22-2008, 04:03 PM
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It really all depends on if your speedo is off or not. FoMOCO allows for a 3 MPH variation. you'll need to check your mph on a flat measured mile (i.e. 2 mile markers with no exits around them on a straight HWY), set cruise at 60MPH and time the distance between the mile markers, (or just use a GPS). 60 seconds to a mile at 60MPH. If it takes you more than 60 seconds then your speedo is reading faster than you are going, if it takes less than 60 seconds then your speedo is reading slower than you are going. Of course this test is to judge whether or not you need to have your PCM recalibrated for a larger tire.
#43
10-22-2008, 04:33 PM
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in the independant test result that I saw Lucas actually decreased fuel lubricity.....PM me and I will send you the link to that discussion this weekend
#44
10-25-2008, 11:47 PM
