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3.21 vs 3.92: The Last Word
- Thread starter cj7
- Start date
SnowBlaZR2
Fuel Economy Champion
Last edited:
StuartV
Ram Guru
I WISH I could look forward to a fuel cost of $2.75/gallon when I get my next truck (which I'm hoping to be soon).
SnowBlaZR2
Fuel Economy Champion
Yeah, but not knowing what fuel costs will be, figured it would be more useful to look back at what you might have seen with a different rear end in your current truck.
Assuming $5/gallon for the next three years, and no other variable changes:
ferraiolo1
Spends too much time on here
So $80 a month saved. That’s with 2mpg difference. Which we all know is more like 4-5 on a highway at speeds.
SnowBlaZR2
Fuel Economy Champion
No, it isn't. You're lucky I'm giving you 2 mpg instead of 1 with your 21.5 mpg.
SnowBlaZR2
Fuel Economy Champion
National averages, assuming that $5/gallon becomes the norm, and living in @ferraiolo1 fantasy land:
ferraiolo1
Spends too much time on here
I’ve shown my fantasy land average over a long period of combined driving.
That kinda makes it the real world.
Sent from my iPhone using Tapatalk
That kinda makes it the real world.
Sent from my iPhone using Tapatalk
SnowBlaZR2
Fuel Economy Champion
ferraiolo1
Spends too much time on here
All the mpgs when you’re engines turned off sitting in traffic.
I’d get 50mpg average if I did that!
Sent from my iPhone using Tapatalk
I’d get 50mpg average if I did that!
Sent from my iPhone using Tapatalk
SnowBlaZR2
Fuel Economy Champion
Idahoktm
Spends too much time on here
Here are numbers that are specific to me. Driving 95% city, 3.21 gears will not yield a mpg advantage but I know how sensitive the 3.21 crowd can be, so I gave them a 1 mpg advantage. 
nc_beagle
Ram Guru
All arguments aside, I think my 3.92 did come in handy pulling a stump out of the ground at lunch We had a 20' Emerald Green Arborvitae taking over some front windows so I cut it down to about 3', wrapped tow straps around it and eased it out. Now, if my wife asks anyone, it was squirrels that tore up the bushes between me and said stump....
BowDown
Spends too much time on here
I easily get 22.x-23 on the highway at 74 and 72 mph. I average high 17-18 mixed driving 70/30 city/highway
BowDown
Spends too much time on here
Here are numbers that are specific to me. Driving 95% city, 3.21 gears will not yield a mpg advantage but I know how sensitive the 3.21 crowd can be, so I gave them a 1 mpg advantage.
View attachment 130355View attachment 130356
3.21 mixed city driving
I get roughly the same every week, 420-430 miles per tank (26 gal refilling with 23 gal). No sensitivity here, it is what it is
SnowBlaZR2
Fuel Economy Champion
BowDown
Spends too much time on here
but at what speed and over how many miles? IIRC your 20 mpg pic was based off 49 mph whereas mine 21.5 was based off 73 mph and we all know the trickery in the above pic
That's an average speed of 72mph driving Dallas through Houston (at 9AM), not 49mph or a quick reset of the fuel mileage screen while driving slow.
Prior to getting into Houston during morning rush hour, I was at 22.x
Here's a full tank average, mixed city and highway in North Dallas, avg speed is 39 mph over 435 miles
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Dewey
Spends too much time on here
I heard your truck was one of the rare prototypes that was accidentally released from the factory with 2.29 gears but was mistakenly listed as 3.92’s.
StuartV
Ram Guru
4 Lo and I don't think it would have mattered what rear end you had...
