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Discussion Starter #1
Hi all

I know we don't buy these trucks for fuel mileage but have any of you check your mileage manually.
What I'm getting at is my 2018 2500 cummins crew cab with Automatic says I'm getting 22 so I checked it
the old fashion way, 19.7. Done it a few times and it is consistently 2 less.

How are the rest of you doing?
 

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That is about normal for me too. I use an App that tracks my MPG, based of fuel fill ups and millage.

Tends to be about 2MPG difference.
 

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Hi all

I know we don't buy these trucks for fuel mileage but have any of you check your mileage manually.
What I'm getting at is my 2018 2500 cummins crew cab with Automatic says I'm getting 22 so I checked it
the old fashion way, 19.7. Done it a few times and it is consistently 2 less.

How are the rest of you doing?
I was getting 12-16L on highway doing 110km/h and I deleted it now and get 9-11L on highway doing 110km/h

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Mine has historically run about 1-1.5 MPG high, and under ideal conditions I have gotten near 24 MPG, readout showing over 25, this with the CC set at 70-75 most of my trip.

All depends on how and where you drive and which way and how hard the wind blows.
 

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I have done mine manually since day 1 (just for fun) The readout is consistently 2 (give or take) higher then reality. My best tank was 18.3 and avg over the past 30K is 15.6.

.
 

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I was getting 12-16L on highway doing 110km/h and I deleted it now and get 9-11L on highway doing 110km/h

Sent from my SM-G960W using Tapatalk
Those #s mean nothing off your display once deleted. Never seen a 13+ truck ever get that much of an improvement after a delete either.
 

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Those #s mean nothing off your display once deleted. Never seen a 13+ truck ever get that much of an improvement after a delete either.


People act shocked when I tell them I didn’t see a mileage change when I deleted. The lil bit I did gain probably came from the weight reduction of the factory exhaust. Lol

I averaged just under 20mpg stock with a best tank of 22.12mpg. Put wheels and mud tires on and dropped it to 17mpg Highway average. I swapped out my MTs for ATs and went back to 19mpg. I’m filling up today after running my first tank with the tow tune. I’ve been running the street tune.


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On the highway I almost always run over 24 MPG, but i keep it at or under 70 on cruise control, usually between 65 and 68. Once in a while I am a little more of a hurry on long trips, 70 to 75 and still always over 22 MPG. Tires are always fully inflated not lowered for a smoother ride like some people do.

I do not manually check anymore, I use to all the time and it was always less then 1.5 MPG off, and sometimes lower sometimes higher. I mostly always fill up at the same station using the same pump. When you do not have many stations selling diesel near you, that is what you do. I also fill up the same way, fill till it clicks, wait a second then go till it clicks again. I figure the meter might be more accurate then hand calculating. Different pumps shut off at different points so how much you pump in is not 100% accurate to how much you used between tanks.
 

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Discussion Starter #10
Thanks all. My truck is not deleted. Strange thing is I came from a Ram Eco diesel and hand calculations were only off
by .1 to .3.
 

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I noticed the same thing about the EVIC. I use the scangauge2 and got it really close to perfect (-/+0.2gl over 30gl). It is a very nice little gauge. One thing I realized is, The EVIC is not based on what is in the tank. I think it is using a 60-80 mile loops or something like this to cal calculate fuel consumption and calibrated with a low sample rate for data. With the scauge2 the data rate is much higher and this makes it more sensitive and accurate. That said. On a trip of more than 60-80 miles the EVIC will catch up and match the scanguage2. Also, the miles given are true up to the last 1 gallon when the low fuel warning light goes off. The 3gl reserve light is true too with the 50 mile indicator.

I use the Instant mpg indicator as a load indicator kind of. Many time it does not take much to get over the 20 mpg bar.

Last trip I did was on the turn pike I80/90 & I75, 250 miles one way. I did not use the cruise control and kept an eye on that little mpg bar. First part of the trip (75) was around 80 mph then when in Ohio it was speed limit +2mph. Return was the same. Well it ended up to be around 27 mpg on the evic and scangauge2, also I was close to half a tank and drove 400 miles.
As long as you are not going up and down or stop and go traffic, you can get some nice numbers out of this truck. I think 60mph is the sweet spot but it is hard to keep it that slow. So far with 15,000 miles on it, I get with 29gl (most of my fill up) between 400 and 700 miles.

Don't read too much in to this, just sharing some thoughts. :wink2:
 

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That is normal but consistent for the overhead to be off a couple or miles. Even back to my 99.
 

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I think it is using a 60-80 mile loops or something like this to cal calculate fuel consumption
I think it calculates actual fuel pumped, when I was keeping track of fuel pumped into the truck, if you look at the fuel filter life gauge it tells you how many gallons of fuels used since it was last reset. It was surprisingly accurate with my tracking of gallons pumped.
 

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Don't know whether if they have changed or not but they usually calculate until reset. They are just off a bit. Maybe due to chips, tires, etc.. Most have an instant mode too. Just assume it is always off consistently. My thermometer is consistently off about 3% too.
 

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Those #s mean nothing off your display once deleted. Never seen a 13+ truck ever get that much of an improvement after a delete either.
I wrote a post back a while, but it is possible to correct the display. Takes about 100-150 hours to dial it in.

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I'm I'm still getting over 750km to a tank so I'm happy

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Ok, so around 14+ mpg or 16 ltrs per 100km
 

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I wrote a post back a while, but it is possible to correct the display. Takes about 100-150 hours to dial it in.

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Yes, so at this point, after deleting they certainly are not accurate.
 

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Yes, so at this point, after deleting they certainly are not accurate.
It's controlled in the tuning, the issue is the way majority of tunes are made make the indicator even further off. Especially in higher power tunes. I've got mine to within a tenth.

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