Ford Mustang Forums

Ford Mustang Forums (/forums/)
-   V6 Tech (http://www.allfordmustangs.com/forums/v6-tech/)
-   -   3.73 gears effect on gas milage? (http://www.allfordmustangs.com/forums/v6-tech/425921-3-73-gears-effect-gas-milage.html)

Zoranan 03-21-2013 11:27 AM

3.73 gears effect on gas milage?
 
Hey guys, I am planning on doing the 8.8 swap on my 1998 V6, and originally I planned on putting 3.73 gears in the 8.8 rear end before I installed it on my car, however my car is a daily driver and I want to know how badly these gears will affect my MPG. Maybe I should do the 3.55's or just stick with the stock 3.27's that are in the GT rear end?

Let me know what you guys think, I want to improve acceleration without hurting gas mileage too badly

P4452 03-21-2013 01:50 PM

I found the 3.27's in the GT rear I picked up to fit my V6 auto quite nicely. No figures on MPG, as this is not a car I drive often.

Lower gears (3.73, 4.10, etc.) will, generally, give you better city mileage. Taller gears (2.73, 3.08, etc.) will, generally, give you better highway mileage. 3.27 and 3.55 are middle-of-the-range.

The lower gears basically reduce engine load, making the same amount of torque act like more torque(requires less throttle to accelerate at the same rate). The taller gears do the opposite, but the reduction in engine RPMs reduces friction at cruising speeds.

If it's worth any comparison, I have a Scangauge II I use to track MPG, mostly in my GT. At 30 MPH cruising in 3rd gear it tends to score around 17 MPG. When I shift to 4th and hold 30 MPH it scores 24 MPG. The difference between the gears is 33%(1.33 vs 1).

The difference between 2.73 and 3.27 is about 20%(3.27/2.73). Going from 2.73 to 3.73 is roughly 37%. Remember, though: that's a 20 or 37% increase in torque at a certain vehicle speed, but it's also a 20 or 37% increase in engine RPM at the same vehicle speed.

2Manystangs 03-21-2013 02:16 PM

milage mostly depends on how fast you drive, plain and simple...now with 3.73s you may find yourself "getting on it" alot more, however the fun factor is well worth the very slight reduction in mpgs

Zoranan 03-21-2013 04:40 PM

Well I do drive this in town mostly, but I will be driving highway as well. I think for now I might just get the gt rear and bolt it up without changing gears to see how I like it. Worst case I swap them later i guess. I'm upgrading slowly as I get the money.


All times are GMT -4. The time now is 08:19 AM.


vB.Sponsors
Copyright © 2002-2010 All Ford Enthusiasts NetworkTM.


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162