Lifetime gas mileage calculation

My 1015 Legacy 2.5i is 7 months old now, and the lifetime mileage for the first 5 months was around 26-27. This included a lot of long distance driving, and daily driving to and from work.

 

I retired and now the car gets driven very little. I have noticed that the less I drive the car, the higher the lifetime mileage. At the moment, the car is showing lifetime gas mileage to be 37, even though I have never calculated the mileage for a tankful higher than 34. Very curious and, I'm sure, inaccurate.

 

Anyone else see this?

Let me guess ... The lifetime mileage started to diverge from reality about the time you passed 7,500 miles on the odometer, right?

 

This is an issue that has been discussed a lot on this forum and elsewhere. Just reset the lifetime EcoMonitor and you should be set for another 7,500 miles or so.

Mine been driven M-F 80 miles each day, tank to tank calculation is about 30-34mpg depends on how much local I drove and traffic.

 

But my lifetime display just reached 60mpg @16000 miles, which is better than most of the hybrid LOL

I see no need to continually calculate mpg's over that much time anyway. Resetting it after each oil change keeps everything most relevant.

 

I reset mine after my 5kmi oil change. I can see a change from winter months to summer months.

It allows you to see semi-recent changes AND if something were to be going on with your car. Never resetting your lifetime meter won't allow you to pay as close attention to that unless you hand calculate every tank(as I also do).

How do you find the lifetime eco monitor?

How do you find the lifetime eco monitor?

 

Info button-->bottom icon looks like a clover

 

Resetting or customizing Eco Monitor Home-->arrow over-->Click on Info icon (not customizing icon)

How do you find the lifetime eco monitor?

 

If you have a Limited, it will be under Info, then EcoMonitor.

 

I've only got 700 miles on mine, but have definitely found that the lifetime mileage is less accurate than the trip average, which is less accurate than real consumption. It seems like real consumption is about 3mpg less than lifetime.

 

Not that I'm bitching. It's a gimmick (I always calculate my economy) helpful for figuring range on the fly.

I only have the base model

You have eco monitor exactly where we explained.

Base/Premium/Limited all have the same exact radio.

Only difference is extra USB and Ipod capabilities on Premium and Limited models.

Navigation is also add-on but has nothing to do with what we are discussing.

Base/Premium/Limited all have the same exact radio.

 

Not for the 6th Gen. Legacy. The unit for Base trim, with a 6.2 inch display, is made by Clarion. For Premium and Limited trims, the unit with the 7-inch display is made by Fujitsu Ten.

Not for the 6th Gen. Legacy. The unit for Base trim, with a 6.2 inch display, is made by Clarion. For Premium and Limited trims, the unit with the 7-inch display is made by Fujitsu-Ten.

 

Show me.

Show me.

 

For starters, it should be obvious that head units with different screen sizes are not "the same exact radio."

 

Beyond that, the original assertion is yours, so the burden of proof is yours, too.

 

From the 2015 Legacy/Outback Owner's Manual, pages 5-4 and 5-5 ... Clarion HU (left) vs. Fujitsu Ten HU (right):

Now that summer is here, I see a great improvement in my dismal gas mileage -- 28.2 mpg on last fillup as opposed to 20.3 mpg in February.

 

Over 4562 miles, the average has been 27.6 mpg, October to June.

 

Mostly 30-40 mph on country roads with little or no traffic. Very disappointing, really, though I expect it will be better by the time I complete the year in October. It won't be as high as 30mpg, however.

 

That's as measured at the pump at every fillup.

 

I like the car, even though it is clearly a bit of a lemon (the 2015 Legacy, I mean, not the particular car I took delivery on). It drives like a much more expensive car, and that's a good feeling. Perhaps it is merely heavier than the Honda Accords I have previously owned.

I found this as well

http://i.ebayimg.com/00/s/NDgwWDY0MA==/z/uYoAAOSw3xJVXw9r/$_4.JPG

My 1015 Legacy 2.5i

 

Did Canute the Great drive this car when he invaded England?

Let me guess ... The lifetime mileage started to diverge from reality about the time you passed 7,500 miles on the odometer, right?

 

This is an issue that has been discussed a lot on this forum and elsewhere. Just reset the lifetime EcoMonitor and you should be set for another 7,500 miles or so.

 

 

?

 

any particular reason y the software supposedly reads better within a 7500 mile interval ?

 

is this fact or fiction ?

is this fact or fiction ?

 

As I indicated in my original post, it has been reported anecdotally by many 2015 Legacy and Outback owners who have passed the 7000-8000 mile mark. No one has reported it occurring at less than 7000 miles.

 

any particular reason y the software supposedly reads better within a 7500 mile interval ?

There have been many theories proposed here and on the Outback forum, some more reasonable than others, but it's probably due to truncation of the "total fuel used" data value (i.e. the data value overflows the memory space allocated to store it). It seems pretty clear to me that at some point the "lifetime fuel" value used to calculate lifetime mpg stops increasing, while the "lifetime miles" value continues to increase normally. But only Subaru has access to the hardware internals and the software source code, so only they can know for sure.

thats a plausible theory ....

 

it sucks that the software is written like that. as if there was some kind of 1980's memory limitation in the hardware or something like that .... you'd think they would have sprung for an extra GB if the programming was meant to store lifetime statistics ...

 

i am coming up on 15 k miles soon. so I think that's a memorable point to reset the lifetime as well as other statistics and see how the numbers read over the next 7-8 k miles.

 

been saving my fuel receipts and documenting all my fill ups so i guess I'll jot down the lifetime readout before i zero it out. just to have something to compare later on.

 

so it seems lifetime is not really lifetime ...

Yeah, I had to reset mine yesterday before leaving for a trip. I am at 11900+ miles and it was reading 40+ mpg. in a 3.6R!

I wish.

 

Seems to be doing fine now at 27ish mpg for most of my freeway trip (which was 75-85 mph steady speed).

 

I average 21/22 usually per tank with my mixed city/freeway (and lead foot) style of driving.

home now and it's still reading 27ish, so I guess the rule of thumb is reset every oil change.

 

Kept my speed under 75 on the way back. Getting decent mileage for a 3.6R. Well, it's decent for me since I used to average 19mpg per tank in my BMW.

 

http://i768.photobucket.com/albums/xx321/chowser51/asqw.jpg

i wish mine worked right, im in the 60s, i am sad about the eco monitor. 17K miles

Again, Ray just reset the lifetime and all will be good.

i use trip b, 27.7 for 10K, i just hoped for a LIFETIME mpg reading like the POS is supposed to do, i dont want to reset it, I want something from Subaru.

It's probably a 8bit small flash memory EEPROM, so the mileage going up doesn't surprise me as it likely stops or resets the gallons consumed when the internal storage limit is reached.

We're talking Atari and Nintendo technology here...

 

I'm sure when they say Lifetime, they don't intend it to calculate the entire time you own then vehicle, but more so a service life which would be oil change intervals or the internal storage limit is reached;)

 

http://lowres.jantoo.com/business-in_tray-in_tray-file-filing-intray-08131428_low.jpg

Tons of useful information here. Thanks to all. Only one thing - I have not been able to find any way to reset my lifetime mileage, despite instructions given by others. 2015 2.5i Premium.