DIC displayed mpg vs true calculated experiment

[aseibel]

Made a trip to the in-laws over the weekend and wanted to pay close attention to the DIC's ability to accurately gauge fuel economy. The wife demanded to take her new car instead of my truck. So we took the 2021 GMC Acadia V6. I'm guessing the same technology is used in the trucks. DIC trip was reset with each fillup.

 

All data is over a 3 day span from this past Saturday to Monday. Temps were below 0F for the entire trip. Tank 1 & 3 were pretty much completely highway driving with no cold starts in between. Tank 2 included a cold start at -20 with around 25 minutes of warmup before we left. Interesting to see how close the numbers are for tank 1 & 3, while the DIC reading for tank 2 is about 10% high.

 

Tank #     Miles     DIC       Actual (hand calculated)

   1           354.5     20.9       20.86     driving generally NW

   2           181.9     21.4       19.53     driving NW first half, parked for 36 hours, then driving SE

   3           288.4     23.5       23.97     driving generally SE

[dieselfan1]

So tank 2 had all the idling, the other two no idling?

I drove my lifted truck one super cold day last week. I warmed it up for over 30 minutes in the morning and two remote starts in the evening (20 minutes). -29 in the morning and around -15 that evening. I filled up and reset everything the day before. I drove 62 miles round trip around 50 mph max mostly 40mph and got 10 mpg avg. that day on the dic last 50 miles. Next day I warmed it up for 20 minutes and drove 1/4 mile to fill up again. Took 7 gallons so actual was 9 mpg.
Small sample size for sure but shows it's close and how much they suck down when it's cold. Especially with a big lift and tires.
I also ran it in 4th and 5th gear. Never saw 6th. Never saw more than 160° on the tranny either.
BTW I run 92 ethanol free premium. I'm not sure how that factors in.

Sent from my Pixel 3 using Tapatalk