Change to 3.90:1 final gets me amazing MPGs!

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StickyLifter

StickyLifter

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Okay, so hear me out. Due to gas prices getting rather ree ree I've started analyzing my driving style and I've discovered that I can peak at over 24mpg indicated on the dash by cruising at around 80mph with the lower final gears. It stays in MDS mode a lot longer now, and drops to four cylinders a lot more often. This gets me thinking about going with a 4.30:1 final so that I can cruise up hills above 2500 rpm in 6th and stay in MDS all the time while cruising. I just did a 200 mile round trip and raised my indicated MPG from 16 to 19.4mpg just by hypermiling up and down the hills. Here is the weird part:

Why is RAM team ditching our beloved Hemi over CAFE when they don't allow cruising in 7th/5th gear WHILE staying in MDS mode? ETorque would help this situation even more, and so would a 6.4L with MDS. What gives? When you have MDS you want more RPMs during light load cruise so you stay in MDS longer. I bet I could AVERAGE 24mpg at 80mph if I had a 6.4L, or eTorque, and some light aero mods would be bonus.
 

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RLJ10X

RLJ10X

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Your dash says 19.4. And if your truck is like mine, the dash Lie-O-Meter is usually about 9% optimistic. That means you're getting about 17.5 (I'm guessing) which would be about right.

I doubt you've reinvented the wheel.
 
dhay13

dhay13

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Best I ever got in mine was 19.85 in my 2013 with 3.55s hand calculated and I was trying to maximize it.
 
Z

zrock

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Had to convert mine over to MPG since im in Canada but i get about 21 on the hwy and 28 city.. Just by watching your mpg's on the screen you can find the sweetspot where you can gain quite a bit when i first got the truck i was 20 - 30% lower, spent the first 2 months watching the tatle tale and adjusting my driving style.
 
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Wild one

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zrock said:
Had to convert mine over to MPG since im in Canada but i get about 21 on the hwy and 28 city.. Just by watching your mpg's on the screen you can find the sweetspot where you can gain quite a bit when i first got the truck i was 20 - 30% lower, spent the first 2 months watching the tatle tale and adjusting my driving style.
Click to expand...
Stand a small bottle up in the box and learn to drive so it doesn't tip over or slide around the box,and you'll be amazed at how much better the milege and brake life becomes. Also keep the rpm under 2,000,as a V8 will always get better milege when you keep it under 2,000 rpm,the intake and exhaust pulses on a stock engine work more efficiently
 
yogibear18

yogibear18

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Gas mileage is not taking an instant reading from the dash, you should be taking from a fill up, reset your trip meter drive say ex tank close to empty or gas light comes on refill take note of trip miles and how many gallons of gas it took to refill your tank simple math you learned in elementary : total miles driven/ gallons of gas to refill = MPG not by instant reading on dash . Just saying… not being a d!ckhead
 
Black1500Ram

Black1500Ram

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Yeah this one’s hard to believe. Especially at 80mph.
If you’re on highway tires, running 60mph, running downhill both ways with the wind at your back, then yeah sure you might get 24mpg.
 
Z

Zoe Saldana

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StickyLifter said:
Okay, so hear me out. Due to gas prices getting rather ree ree I've started analyzing my driving style and I've discovered that I can peak at over 24mpg indicated on the dash by cruising at around 80mph with the lower final gears. It stays in MDS mode a lot longer now, and drops to four cylinders a lot more often. This gets me thinking about going with a 4.30:1 final so that I can cruise up hills above 2500 rpm in 6th and stay in MDS all the time while cruising. I just did a 200 mile round trip and raised my indicated MPG from 16 to 19.4mpg just by hypermiling up and down the hills. Here is the weird part:

Why is RAM team ditching our beloved Hemi over CAFE when they don't allow cruising in 7th/5th gear WHILE staying in MDS mode? ETorque would help this situation even more, and so would a 6.4L with MDS. What gives? When you have MDS you want more RPMs during light load cruise so you stay in MDS longer. I bet I could AVERAGE 24mpg at 80mph if I had a 6.4L, or eTorque, and some light aero mods would be bonus.
Click to expand...
When you do the math - it isn't worth it:
$$$$$$$$ Cost of new Gears/install
Divided by Gas Cost Savings e.g. going from 24mpg to 26 mpg = 2 mpg savings

That will give you the # of years to break even.

==================


Post your calculation here.
 
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