moturbopar
1/2 ton status
HI I was wonderin how much fuel miliage you guys have lost switching to a 14bolt axle compared to the 10 bolt/12bolts?
CK5
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MPG loss from switching to 14bolt?
- Thread starter moturbopar
- Start date
xpndbl3
1/2 ton status
shouldn't really be that large of a loss. typically we change gearing at the same time, so who knows how that would affect it. personally i went from 3.73 to 4.56 gears, so that alone would change mileage
if you get the same gears, and the same diameter tires then you are basically adding 150-200 lbs of wieght, but essentially nothing else will change
just think of it as having a passenger along for the ride
you could get into arguments about rolling resistance of a 14b vs. a 10 bolt...
you could also get into arguments about the added aero-drag of the 14 bolt...
but effects are negligable
just think of it as having a passenger along for the ride
you could get into arguments about rolling resistance of a 14b vs. a 10 bolt...
you could also get into arguments about the added aero-drag of the 14 bolt...
but effects are negligable
Yea, I went from 3.42 to 4.56 so I couldn't check for a long time. But I know now (using GPS) that I get what I was supposed to out of the factory...about 12mpg
4xcrazy
3/4 ton status
i lost about 5 mpg,,,
then again it could be the combo of the lift, bigger tires, heavier drivetrain, and my fatass getting fatter
and also my gearing went from 3.42's to the 4.11's in it now
then again it could be the combo of the lift, bigger tires, heavier drivetrain, and my fatass getting fatter
and also my gearing went from 3.42's to the 4.11's in it now
Might get better!
I've seen a few trucks that had 2.73's,2.56 or 3.08's 1/2 ton axles actually get 2-4 MORE miles per gallon when 3/4 ton axles with 4.10's or 4.56's were installed,due to the gearing being better suited to the big tires they wanted to run (36")...kept the motor from lugging,and in its best power/torque band..this is not always true in highway driving though..
I've seen a few trucks that had 2.73's,2.56 or 3.08's 1/2 ton axles actually get 2-4 MORE miles per gallon when 3/4 ton axles with 4.10's or 4.56's were installed,due to the gearing being better suited to the big tires they wanted to run (36")...kept the motor from lugging,and in its best power/torque band..this is not always true in highway driving though..
4xcrazy said:i lost about 5 mpg,,,
then again it could be the combo of the lift, bigger tires, heavier drivetrain, and my fatass getting fatter
and also my gearing went from 3.42's to the 4.11's in it now
The only way you're going to convince me you LOST 5mpg is if you show us where you had your speedo re-calibrated AFTER you swapped axles and axle ratio. Once you change tire size or gear ratio you cannot calculate fuel mileage using the odometer until you've had it re-calibrated.
beater_k20
Banned
mechted said:
wouldnt the 14 bolt actually be more efficient, since the axle shafts do not support the weight of the vehicle, thus making them easier to turn?
aero drag on a rear end housing?
4xcrazy
3/4 ton status
i'm really only guessing, but with the known mileage to work, and the amount of fuel used, i am getting around 10,,,maybe 12 mpg.
and the recent trip to SoCal just about killed me on fuel as well
and the recent trip to SoCal just about killed me on fuel as well
i said the effects are negligablebeater_k20 said:aero drag on a rear end housing?
im working on a lab report involving aero drag on an airfoil, comparing it to drag of a cylinder... so i kinda extrapolated, sorry
resurrected_jimmy
1/2 ton status
My gas milage went up when I did my 14 bolt swap, or maybe that was just the fact that it could move under its own power again instead of sitting on jackstands with a grenaded 12 bolt for the 3rd time
4xcrazy
3/4 ton status
the other thing, i believe the only reason my fuel mileage went down is mainly from the gears, going from 3.42 to 4.11 was a little bit of a jump.
maybe alittle more areo drag from the lift i dunno.
maybe alittle more areo drag from the lift i dunno.
beater_k20
Banned
4xcrazy said:
you have 4.10s, 35s, and overdrive. that gearing is VERY close to where your Blazer would be stock. there's absolutely no reason to lose fuel economy by that much. did your driving style change at the same time?
4xcrazy
3/4 ton status
beater_k20 said:
yeah i do now, just recently got the tires, and for quite some time, when i first got the 14bff with the 3.73's i was still running tires at 31".
then gear changes to 4.10's and 33"tires did alittle more, and now with 35"BFG's...it's coming around
the mileage has changed some with these new larger tires, just haven't figured it out yet, JUST got them last week
i was gettin around 10 or 11 with 3.73s and 35s with the 10b's. i now have 5.13s in a 14b, but its still not completely together yet. milage should be interesting until i get the 40s
89GMCSuburban
1/2 ton status
Uhh, he added a lift, driveline, and bigger tires. You can't expect to gain something like 5" of tire, 4" of lift and heavier driveline and have it NOT lower mileage. With 3.42's and 31's I'd get 14, with 36's and 4.10's (adjusted speedo as well) I get 8.
4xcrazy
3/4 ton status
89GMCSuburban said:
this is basically what has happened, only i didn't figure 8, i was figuring somewhere around 10, maybe 12 depending on how light on the foot i was,,,but with gas prices the way they are,,,,YES, my driving style HAS changed,,,VERY easy on the go-pedal
blackblazer717
1/2 ton status
i lost about 4 or 5 miles to the gallon
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