Timberline Transmission and MPG

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KetMalice

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So this is just an FYI. Also curious if others noticed this. When my Timberline was brand new a full tank would show and give me ~420 miles a tank. My MPG average started slowly creeping up (better mpg) but my range was creeping down, what the display said and what I was actually getting per tank.

My transmission has been reprogrammed twice, and I noticed it’s doing the same exact thing after the transmission is reprogrammed. I get about 420 miles a tank, MPG average goes up, but I end up at about ~380 miles per tank.

I know this transmission is a learning transmission but that’s a pretty wild swing. I drive fairly conservatively and use eco mode. How is the transmission getting jerkier as time goes on and miles per tank goes down but MPG average goes up.
 

rd618

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The computer is just calculating averages, when it's re-set it has to learn your driving and fuel usage. When it lacks data it uses factory programmed value until you've driven enough. The computer is only using the last x miles or so to give you an estimate.
As for the MPG going up but tank going down. The calculations are not the same, they are looking at similar metrics but not the same calculation. One is estimating how far you can still go if you keep driving the way you have been over the past x distance (as you add more distance, the earlier distance falls of). the other is looking at what you have been achieving from a set point to current (ongoing average including recent and earlier).
If you reset everything at the same time and drive 50 miles and the calcs are off wildly, such as ongoing average fuel economy reads 23mpg, but the DTE reads 250miles with a full tank, you have a calc error which might need to be reprogrammed (i.e. DTE is reading wrong fuel tank size, or it's assuming worse than average reading due to towing)
 
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KetMalice

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I kind of get using factory data to calculate things. But I ran the tanks basically dry to test (I always do on a new vehicle) and it physically went 40
-50 miles farther on the transmission before it learned my driving habits, which is not that aggressive.
 

Jerald Cook

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I haven't been able to find anything in the owner's manual of my 2020 to explain the estimated range, but in my previous vehicle (a Honda, so it could be entirely different) the range was based on the average fuel economy for the last 20 or so miles. So if you refueled in the middle of a highway trip the range estimate would be vastly different from a mid-city driving trip. Even if your driving mix is pretty uniform, with my 27 gallon tank, a difference of just 1. 5mpg over the past 20 miles could drop a tank's range by 40 miles if the same type of calculation is used.
 

TimberExpy

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Yeah this will adjust substantially depending on your consumption over the last X number of miles.

For example, when I fill the tank after a week of short trips/city driving, the range estimate is somewhere in the mid 300s. But when I fill up on a 1000-mile road trip after being at cruising speed for hours at a time, the range for a full tank jumps up to about 440 miles.
 

ElectrifyCLT

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Yeah this will adjust substantially depending on your consumption over the last X number of miles.

For example, when I fill the tank after a week of short trips/city driving, the range estimate is somewhere in the mid 300s. But when I fill up on a 1000-mile road trip after being at cruising speed for hours at a time, the range for a full tank jumps up to about 440 miles.

What are you getting on those 1000 mile trips? I'm about to take one in a few weeks and am a little worried about the droning and MPGs. Getting about 18 or so on 45-55MPH roads.
 

dlcorbett

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My nav with the same engine gets 22mpg on the hwy
 

duneslider

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I have a max and get 18-21mpg on long drives, depending on terrain, weather, speed. Speed limits in a lot of places I go are 80mph which isn't great for fuel economy.
 

TimberExpy

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What are you getting on those 1000 mile trips? I'm about to take one in a few weeks and am a little worried about the droning and MPGs. Getting about 18 or so on 45-55MPH roads.
For segments where I’m doing about 78 mph, I’m getting an average of just over 20 mpg. But I’ve noticed that for long stretches where I’m going about 55-65 mph, the average is closer to 25 mpg. So it looks like the sweet spot for max average mpg is somewhere around 60. I use cruise control as much as possible, but of course, changes in elevation will affect this.

This is in a Timberline with the stock wheels and tires.
 

ElectrifyCLT

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That's incredible given you also have the Max Trailer Tow. I'll need to pay closer attention to see if I can get there. My road trips are relatively flat, so there's no reason I shouldn't be able to get there.
 

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