Fuel efficiency diff between 3:73 and 3:55
05-30-2012, 06:57 PM
#21
Senior Member
05-30-2012, 07:29 PM
#22
Originally Posted by Legendsk
3.73 - 3.55 = 0.18
0.18 / 3.55 = 0.0507 = 5%
If 60 mph = 1,700 rpm (with 3.55), then
60 mph = (1,700 x 1.05) <with 3.73> = 1,785 rpm
measurable, but hardly noticeable
If mpg = 20 (with 3.55), then
mpg = 20 x .95 (with 3.73) = 19 mpg
measurable, but 1 mpg less than the effect of a 2 mph headwind
If 720 miles per tank (36 x 20) <with 3.55>, then
(36 x 19) = 684 miles per tank <with 3.73>
measurable, but I was going to have to stop and pee somewhere before
those 36 miles anyhow?
In the real world the 5% difference is the calculated difference and probably represents the absolute maximum difference. The effective difference mostly disappears among all the other environmental and operational factors that affect the truck. Only if you are going to operate at the extreme edge of some parameter, like towing at the absolute limit for the truck, drag racing, hauling loads right at GVWR, etc., would it really matter.
0.18 / 3.55 = 0.0507 = 5%
If 60 mph = 1,700 rpm (with 3.55), then
60 mph = (1,700 x 1.05) <with 3.73> = 1,785 rpm
measurable, but hardly noticeable
If mpg = 20 (with 3.55), then
mpg = 20 x .95 (with 3.73) = 19 mpg
measurable, but 1 mpg less than the effect of a 2 mph headwind
If 720 miles per tank (36 x 20) <with 3.55>, then
(36 x 19) = 684 miles per tank <with 3.73>
measurable, but I was going to have to stop and pee somewhere before
those 36 miles anyhow?
In the real world the 5% difference is the calculated difference and probably represents the absolute maximum difference. The effective difference mostly disappears among all the other environmental and operational factors that affect the truck. Only if you are going to operate at the extreme edge of some parameter, like towing at the absolute limit for the truck, drag racing, hauling loads right at GVWR, etc., would it really matter.