So take this for what you will but over the last week or so I've been testing my average mpg according to the trucks onboard computer. So.... I commute about 40 miles on wide open interstate with no traffic interference VERY early in the morning. What I've been doing is as I merge onto the interstate setting the cruise at the speeds below and once it's set I reset the Mpg. Due to no traffic when I commute I'm able to make the whole 40 mile trip without having to turn off the cruise or brake. The below listed mpg's is what it showed as I turned off the cruise control and exited the interstate.

65mph ......22.3mpg
70mph.......24.5mpg
75mph.......21.7mpg

I've tested it several times and these numbers are consistant. So apparently 70 is the "sweet spot" if you can tolerate driving that speed.

 

Good info - thanks.

 

I just took a trip from South FL to Tennessee and averaged 26mpg on the way up that included stop and go, highway and mountain climbs and decents. Avg speed was 65-75mph...did a curiosity test with the E85 on the way home when i got back into FL...FIlled up with E85 and reset mileage...rest of trip home at 70mph no traffic all highway i got 17.5mpg...it was only 10 cents cheaper than Regular 87 octane gas and much lower mpg just in case any one was interested...have had this result numerous times with the e85...

only modification to Durango is a cold air intake and this is the V6 SXT model and it was fully packed with luggage and baby stuff..

 

E85 is crap corn fuel
STEVE

 

Yeah, might be important to note with my testing that mine is a '13 R/T with AFE cold air, hypertech and flow master catback. And that was on 87 octane Chevron

 

Doesn't the HEMI engine require 89 octane ?


Auggie

 

89 is recommended. Ive run 85 here in Colorado since new. Zero issues.

I run 68-70 mph for the best mpg in my 13 crew. 22 at altitude, 24 at lower elevation with factory michelins. Just put the winters on. Best i get with those is 20 mpg.

 

I've been monitoring the mileage in my 2013 Durango SXT (V6) for the past year. I bought it on 12/2/13 and now that its has been a full year I decided to go back and review it all.

One thing that I question is how accurate the on-board computer is vs doing straight math (Mileage range/miles driven) - I'm guessing the on-board computer is more accurate although I'm always a little pessimistic that the manufacturers boost that # to make it look better.

Anyway - the computer average for the year was 20.2 MPG, the math average was 18.9 MPG. Based on the computer reading my best average for the year was 21.7 and the worst was 17.9. On any given week the difference was an average of 1.3 MPG Off (it fluctuated from 3.2 to .08 ; the 3.2 seems very odd - its the only one that high, the next closest is 2.3) - only twice was the computer reading lower than doing the math manually (by .08 and .04 MPG) .

On average I filled up every 392 miles - the most being 460 miles before needing to fill up. My OCD wont let me do a partial fill-up so just about everything is from about 50-80 Miles left in the range to full. (a few times I see I filled up from about half a tank because of a decent price drop on gas.

I commute 4-5 days a week, 35 miles each way - out of that 25 miles is highway but with NJ traffic it can go from cruising at 75 to stop and go. Most of the driving is just my commute - I can't think of any long trips I had this year - for the first full year I put 19,731 miles on it.

Just a few other interesting things - the average price per gallon I paid was $3.33 ($3.86 being the most, $2.70 the least). The average cost to fill the tank was $69.98 ($84.76 most/$57.00 Least).

(Gas prices dropped in the last 2 weeks where I paid $2.38 this morning and filled the tank for $49.04!!! Thats not in the math above since its outside of the 1 year range I wanted to track...

Anyway - not sure if this is interesting to anyone other than me but thought I'd share.

 

My computer is always 1 mpg better than when I calculate by hand. By hand is much more accurate if you do it consistently over a long period of time.

That said, I have averaged about 21 mpg (by the computer) with my 14 R/T over the last 37,500 miles. (I do drive a lot of highway miles)

 

Noticed the same thing in my Hemi AWD. At 73mph it starts to drop. I've hit a pump verified 25.2 mpg hypermiling at 71 mph. No cruise, and following large vehicles. 22-23 is my long distance normal ave.