In another thread we were talking about how much fuel my 08 F-450 was burning.
Ive been watching it a little closer and heres the latest figures .

It burnt 87 litres to go 272 kms

Fuel costs $133.9 a litre

Can anyone figure out how much per mile /kms Im getting?

 

272/87
3.12 km/litre
1.33/litre/3.12
43 cents/km
Approx
My math may be off but I think you are close to this.

 

Yeah, $0.43/km is your fuel cost on that trip.

But from your post, I'm not sure that's what you are asking.

 

3.12 km/litre
Approx 7.35mpg us gallon at 3.78litres/gallon

 

Thats what i came up with also.
I think that is average possibly for being a stock truck with all the emissions and that gearing

 

So im getting around 7 miles to the gallon?

 

yes. but you must have had around a 1/3 of tank fuel left in the truck correct? There could be several variables that could still throw off that calculation.

First i would check your speedometer and odometer against a GPS for accuracy as the truck could be up to i believe %10 off over or under.

Second being it was just one tank and not several back to back tanks you could have over or under filled it before this trip or over/under filled it at the end.

Third, even parking at a different pump could angle the truck to vary when the pump kicks off when filling up.

The more miles and fill ups added together will give a more accurate reading.

i quickly looked at what others have posted on the 4.88 geared trucks and sounds like the best empty is around 11mpg with one guy saying he got up to 15mpg after dpf delete, which i find hard to believe? but the average looked like 7-10mpg stock w/ dpf. what was your computer average saying. mine is usually about 1-2 mpg high

 

Ill keep track of the next 3 or 4 fills and get a average.

 

I get between 11 and 14 around town when not towing. I have the best (highway) gears available (3.55) and my truck is a bit lighter than yours. Mine is 8800# on a scale with me, fuel and no load. I'd expect that to go up with more fillups and running the tank lower (closer to empty). Your truck is probably 9200-9400# with the bigger axles, wheels/tires, etc.

 

If you want to do some comparison try driving slower. Keeping the rpm as low as possible will help around 2000 rpm or less is the best. On a f 450 that is hard. so if you try to keep it at 2000 rpm you will be at 55 mph. the lower you can keep it the better it will be, that is the reason I did the gear swap in mine going 55 just doesn't work. if your running say 75 on the freeway your turning 2700+ rpm and there goes the fuel mileage.

 

How much (approx.) did the gear swap cost you?

 

Rear Gears are from 650 to 1200 depends on what ratio you want, you will also need a tone ring about 65. here is a list of ratios available for the rear Dana S110
Gear & Pinion Kits - S110 Models
34 Inv. Spline
12.25” (311 mm) Hypoid Gearing
Pinion Nut Part No. 130542
The Kits below include: Two brg cone part# HB105, two cup part# HA102 and qty (12) 130595 cap screw
Mated Gear/Pinion Set Mated Gear/Pinion Set Mated Gear/Pinion Set
Spicer Generation 1 Generation 2 Generation 3 Tooth
Ratio Kit P/N Gear (NSS) Pinion (NSS) Gear (NSS) Pinion (NSS) Gear (NSS) Pinion (NSS) Combo Notes
3.73 511831 130519 130537 132953 132898 132953 139758 41/11
3.91 511832 130604 130535 132954 132899 132954 139759 43/11
4.10 511833 130519 130536 132955 132900 132955 139760 41/10
4.30 512277 130604 130534 132956 132901 132956 139761 43/10 Replaces 511834
4.56 511835 130513 130527 132957 132902 132957 139763 41/9
4.78 511836 130515 130530 132958 132903 132958 139764 43/9
4.88 511837 130517 130533 132959 132904 132959 139765 39/8
5.13 511838 130513 130526 132960 132905 132960 139766 41/8
5.38 512279 130515 130529 132961 132906 132961 139767 43/8 Replaces 511839
5.57 511840 130517 130532 132962 132907 132962 139768 39/7
5.86 511841 130513 130525 132963 132908 132963 139769 41/7
6.14 511842 130515 130528 132964 132909 132964 139770 43/7
6.50 511843 130517 130531 132965 132910 132965 139771 39/6

And the tone rings
16 Tone Ring 1 ABS Models Only
Ratios 3.91-4.10 130770 For 3.73 ratio contact Dana
Ratios 4.30-4.88 130602
Ratio 5.38 130647

The front Dana Super 60 is available in the same ratios, they run 700 - 800
you may need install kits or bearings and oil for them also.

The gears are available from many places the above part numbers are from the Dana S110 parts book. I have seen 3.55 for the axle as well. you will also need to know if your axle has the posi in it or not.

I did the install my self so as far as labor not to sure,
Let em know if you need any more info..