4.10 gearing and MPG
#1
03-31-2006, 10:23 AM
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4.10 gearing and MPG
I've been taking notice that 4.10+ gearing seems to be the best perf. upgrade for the buck. But what does 4.10+ gearing do to MPG on the highway?
Aftert putting my 33's back on I've noticed the OD kicking in and out up hills on the freeway at 70MPH and would benefit from 4.10 or + gears but downt want it to kill any more MPG than what I'm not getting now with those heavy wheel/tires I got on, plus I put the stockers back on for the winter.
THANX
jpn
Aftert putting my 33's back on I've noticed the OD kicking in and out up hills on the freeway at 70MPH and would benefit from 4.10 or + gears but downt want it to kill any more MPG than what I'm not getting now with those heavy wheel/tires I got on, plus I put the stockers back on for the winter.
THANX
jpn
#2
03-31-2006, 12:37 PM
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#3
03-31-2006, 01:01 PM
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From the calulators I have found, assuming 33's are actually 33" tall, and you have approx a 0.70 OD ratio, you'll run about 2050 rpm with 4.10s... add in effective drivetrain/tranny slippage for an auto and you'll be running 2100 rpm+... not necessarily a good highway mileage rpm. Great for acceleration, though.
Going with 3.73 with that setup and you'll see about 1875rpm, after slippage and such it'll be closer to 1950+. A much better highway mileage rpm.
3.55s and 33's should already have you in a sweet spot on flat land rpm at around 1800rpm. Sometimes a truck just has to downshift.
I will say that going with a gear swap, I'd go with 4.10s for the utility of being able to go to larger tires later, and a better performance ratio for get up and go... however, you've effectively ruled out highway mileage by going with beefier tires.
-Kerry
Going with 3.73 with that setup and you'll see about 1875rpm, after slippage and such it'll be closer to 1950+. A much better highway mileage rpm.
3.55s and 33's should already have you in a sweet spot on flat land rpm at around 1800rpm. Sometimes a truck just has to downshift.
I will say that going with a gear swap, I'd go with 4.10s for the utility of being able to go to larger tires later, and a better performance ratio for get up and go... however, you've effectively ruled out highway mileage by going with beefier tires.
-Kerry
#4
03-31-2006, 02:23 PM
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I'll have to see what my tach is in OD now ???
I didn't realize those wheels/tires would end up being so heavy. Evo454 8.5 x17" and MT MTX 33.
Thats all the taller of tire I want to go. Looks way nicer than stock, plus I got a hell of a deal on those wheels $750 all four brand new in box !!!
Something that puzzles me is my tripometer is showing fewer miles than with the stockers but according to GSP my speed between the two are identical. At least around the 60 65Mph range.
I'll probably stick with 3.55 then. I thought if I could get away with a taller gear and add LS I'd do it but my shortest trip from home is 50mi round trip.
I didn't realize those wheels/tires would end up being so heavy. Evo454 8.5 x17" and MT MTX 33.
Thats all the taller of tire I want to go. Looks way nicer than stock, plus I got a hell of a deal on those wheels $750 all four brand new in box !!!
Something that puzzles me is my tripometer is showing fewer miles than with the stockers but according to GSP my speed between the two are identical. At least around the 60 65Mph range.
I'll probably stick with 3.55 then. I thought if I could get away with a taller gear and add LS I'd do it but my shortest trip from home is 50mi round trip.