Anybody have Hemi,4.10's, and stock tire size?
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Anybody have Hemi,4.10's, and stock tire size?
I am wondering What kind of mileage your getting with a Hemi engine, 4.10 gear ratio and stock tire size in a dodge ram? I currently have 373's and am going to swap out gears for 4.10's but wanted to know how bad it is going to kill my mileage before I do it. Thanks in advance for your input.
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I am wondering What kind of mileage your getting with a Hemi engine, 4.10 gear ratio and stock tire size in a dodge ram? I currently have 373's and am going to swap out gears for 4.10's but wanted to know how bad it is going to kill my mileage before I do it. Thanks in advance for your input.
If I downsize to OEM 17" wheels with 265/70 17 tires then my gear ratio will be 4.10 effective compared to the OEM 20" wheel setup.
Most are reporting better mileage with 17" versus 20". Maybe this would compare well for you?
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From: GA
(MPH) x (0.67 Ratio) x (Gear) x (336) / (Tire Diameter) = RPM
Stock BFGoodrich Rugged trail 265-70-R17 = 31.4" diameter tire
here's the calculator from Randy's Ring & Pinion to assist...just plug and play (use .67 ratio for our overdrive if looking at hwy rpm's):
http://www.ringpinion.com/Calc_RPM.aspx
4th Gear .75
Gear Ratio 4.10
Tire Size 31.4
RPM's MPH
1500 46
1600 49
1700 52
1800 55
1900 58
2000 61
2100 64
2200 67
2300 70
2400 73
2500 76
2600 79
2700 82
2800 85
2900 88
3000 91
5th Gear .67
Gear Ratio 4.10
Tire Size 31.4
RPM's MPH
1500 51
1600 54
1700 58
1800 61
1900 65
2000 68
2100 71
2200 75
2300 78
2400 82
2500 85
2600 88
2700 92
2800 95
2900 99
3000 102
I too have contemplated upgrading to 4.10's on my Mega Cab more for grunt than MPG increase....MPG is going to be horrific regardless of mods we do to our mega's even if you do everything you find and spend $1000's if your lucky and tune it just right you might get 2-3mpg more, you'll never realize a benefit at gas prices today vs. price of mods... basic fact: an almost 4 ton truck takes alot of gas to get moving....Remember you can see RPM changes from these numbers, but you also have to take engine load into account when you're talking MPG differences....hope this helps...
Stock BFGoodrich Rugged trail 265-70-R17 = 31.4" diameter tire
here's the calculator from Randy's Ring & Pinion to assist...just plug and play (use .67 ratio for our overdrive if looking at hwy rpm's):
http://www.ringpinion.com/Calc_RPM.aspx
4th Gear .75
Gear Ratio 4.10
Tire Size 31.4
RPM's MPH
1500 46
1600 49
1700 52
1800 55
1900 58
2000 61
2100 64
2200 67
2300 70
2400 73
2500 76
2600 79
2700 82
2800 85
2900 88
3000 91
5th Gear .67
Gear Ratio 4.10
Tire Size 31.4
RPM's MPH
1500 51
1600 54
1700 58
1800 61
1900 65
2000 68
2100 71
2200 75
2300 78
2400 82
2500 85
2600 88
2700 92
2800 95
2900 99
3000 102
I too have contemplated upgrading to 4.10's on my Mega Cab more for grunt than MPG increase....MPG is going to be horrific regardless of mods we do to our mega's even if you do everything you find and spend $1000's if your lucky and tune it just right you might get 2-3mpg more, you'll never realize a benefit at gas prices today vs. price of mods... basic fact: an almost 4 ton truck takes alot of gas to get moving....Remember you can see RPM changes from these numbers, but you also have to take engine load into account when you're talking MPG differences....hope this helps...
Last edited by throberts; Sep 27, 2008 at 12:50 PM.
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Thanks guys! Appreciate the info. I actually have 4 inch lift and 315/70/17 and really would like to do 4.56's rather then the 4.10's. Anything would be better then the 373's I have now. The reason I posted question with 4.10's and stock tire size is the ratio is the same as the 315's and 4.56's. Anybody running 315's or 35's with 4.56's and a hemi?