I seem to be getting appx 3-4 MPG lower than I used to a few months a ago... I DID have the latest PCM updates etc, during that time..but it is also 30 + deg colder than say OCT now here in the Midwest. Never had any problems before or after updates. 10500 miles now.
How much of that mileage drop is attributable to colder weather and how much is attributable to the updates?.
I used to get 30-31 MPG on the hwy no problem, but last week on a 400 mile trip never broke 27.5 MPG under same conditions...
What does everyone think?
same problem here I had winter blend in the tank, now that the temp. warmed back up to fall like temperatures here in the Midwest so I put back in straight # 2 diesel from the truck stop. Hope my mileage goes back up.
Also check your tire pressures. Cold air drops PSI. Lower PSI increases rolling resistance, and drops MPG. A LOT. I keep my '14 Summit with OEM tires at 40-42psi. Excellent treadwear so far (just under 10k miles), good ride quality, good fuel economy.
When the fuel is changed to the winter blend (October thru April in Minnesota), you can expect a drop in milage - depending on the outside air temp, the lower, but worse milage also. With mixed driving (50% highway, 50% city) I get 25 mpg in the summer, and it drops to 22 mpg in the winter. If you are mostly highway, you will see less of a drop in milage. I get 30 mpg on road trips in summer, and close to 30 mpg in the winter.
How much of that mileage drop is attributable to colder weather and how much is attributable to the updates?.
I used to get 30-31 MPG on the hwy no problem, but last week on a 400 mile trip never broke 27.5 MPG under same conditions...
What does everyone think?
I don't know. I have been avoiding the updates released after August for just this reason. My recent refueling after a few weeks of in town driving was manually calculated to be 17 mpg. I got 14.5 mpg once on a tank calculation last winter. I don't want that to get any worse.
However, in addition to winter diesel and tire pressure, don't forget to factor in headwinds. Today, heading south on a Midwest interstate I was getting about 27 mpg, but once I transferred to an eastbound interstate I got 31 mpg @ 68 MPH over 100 miles. Both legs were on winter blend and using ACC drafting where possible. I lose several mpg if I can't use ACC drafting.
In crappy conditions last month, on a flat interstate, traveling at 50 mph, my average over 150+ miles was <25 mpg. Ugh.
I try to gauge the wind as I drive, but it's hard. Trees and scrub will not necessarily visually indicate wind for you. I look for windmills, flags, and smoke plumes.
Also check your tire pressures. Cold air drops PSI. Lower PSI increases rolling resistance, and drops MPG. A LOT. I keep my '14 Summit with OEM tires at 40-42psi. Excellent treadwear so far (just under 10k miles), good ride quality, good fuel economy.
I inflated to 42 psi (cold) in the summer. Now that it's colder, I considered increasing the air in the tires until it's 42 again.
However, two thoughts:
1. Not that the stock forteras are great in the snow, but overinflated tires will have slightly less traction than normal.
2. How much headroom do we have? As it warms back up the pressure is obviously going to increase. Anyone running 50+ psi on the stock tires? I really don't want to turn tire pressure adjustment into a monthly chore.
I can concur with the statements around poorer fuel economy up here in Canada over the last few fills. Here has been the calculated fuel economy since June for myself:
No real big highway miles, almost all around town. As stated, dropping off I am sure as a result of the winter diesel. I have recently inflated the tires back up so will see if I notice any improvement with that change. The TPMS was triggered once it got cold here as well so I thought it was time to pump them up. Target psi is around 40-44.
Just did a road trip in my Overland Diesel to the mountains and back, 2287km (1421miles) in colder climatic conditions and averaged roughly 10.1L/100km (23.3mpg) with no fuel conditioner. Highway speed average was around 105-120km/hr (65-75) pulling a small trailer with skis and gear of about 700lbs.
Prior to the trip, I did an oil change and the oil engine life indicator went from 100% down to 83%. Curious if that is an indication of driving normally, pushing it, or barely working the diesel???
Will be happy to see this improve (I hope) when I do the trip again in the summer!!
Just back from a trip Florida to Ohio and return. 3 things contributed to my mileage; winter blend, headwinds, external temperatures.
I drove 77 up and back. I saw mileage of 25 mpg up and back. When into a headwind dropped to 21. Tires pressures at 38 up and back as I inflated once in Ohio. Temps starting out at say 0F dropped mileage to around 18-21 until about an hour once everything was warmed up. Headwinds would drop mine to 24-25 as well. Winter blend I would guess would too but can't tell how much. I am back in Florida and seeing my typical 28-30 mpg around 67 mpg.
I don't know if we see winter blend in this part of Florida (panhandle).
Since I have gone through the Rev E update, I have seen a 1-2 MPG lower average...i have been looking at it closely for the last 1000km's I have done since the update...I cannot attribute to cold weather, since It was cold 1000km prior the update and 1000km after as cold....so not a factor there. As for winter Diesel blends, was already comparing with it, tire pressure was also monitored and made sure all was the same prior and after...As for driving, highway vs city, I have not modified my habits... So REV E has a directly affected my GC's consumption, no questions.
Since I have gone through the Rev E update, I have seen a 1-2 MPG lower average...i have been looking at it closely for the last 1000km's I have done since the update
Due to the relative nature of representing fuel consumption in MPG, an MPG offset is not something that can be directly compared unless the actual MPG values are given (e.g. if you tell us it dropped from 29 to 27 MPG).
Conversely, can you give us the change you observed in L/100 km? That's directly comparable and not subject to the problems inherent to MPG.
It don't matter what I'm driving, diesel or gasser, my mpgs drop in the winter. Different fuel, and I tend to idle a bit longer before taking off.-Rockydee
Hi,
I am also seeing a significant drop in mpg. I have had all the recent updates + the new CAT installed after lots of def issues. It seems to have dropped directly after this work was completed not too long ago. Now cannot get over 21-22mpg. Granted, it is the winter and its been cold however last year at this time did not see such a drastic reduction. Im considering bringing it in for an evaluation- especially if I hear others with this same issue. Ive got about 15,250 miles total.
And, by the way.... for the very first time (have owned many new cars) I just purchased an 8 year max care extended warranty! Purchased on line. Love the car but reliability thus far is questionable. Consumer Reports just gave it an"unreliable, not recommended" evaluation. Hmmmm, dont doubt it.
I tow a travel trailer so this vehicle has been a good fit for me.
The newest updated also killed MPG. I live in a place that doesn't have winter blend. I dropped 5mpg with the newest flash. The reason being is that it doesn't use low end tq to hold hills anymore (to keep out of shudder area of trans). So the trans downshifts more often than it should.
Update:
Mileage has now increased.
Not sure if it's the warmer outside temperature, much less warm up time and/ or different fuel.
But now, almost back to previous around town daily mpg of 25.
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