Gas mileage just keeps getting worse

Yep it’s the same

 

I've put 37K miles on a 2016 TRDOR with the manual transmission and have never cracked 20 despite trying my hardest several times. The manual transmission costs you about 2mpg because of the gear ratio but makes up for it in fun. I honestly wonder if a taller tire might actually help highway MPG as it will lower RPMs a bit. With the added weight of a taller tire, it's likely a wash but I plan to find out soon!

 

"I just don't get it. I only added 1500 pounds worth of metal to my truck, how could the gas mileage have gone down 0.58 mpg?!"

 

"So what if I always shift at 5 grand? HURR DURR EPA SCAM!"

 

Mine is stock

 

I thought I would resurrect this thread to give an update on my mileage now that the weather has warmed up.

The difference in mileage around town is remarkable. I routinely get trip mileage around 20-22 mph now without paying too much attention on throttle useage for trips over a couple miles, whereas during the winter the trip averages were around 15-18 mpg. Late at night when traffic is is essentially nonexistent, I can time lights relatively well, and I watch the throttle going up hills, I can get over 26 mpg in town. Theoretically, according to my Eco app, I could get about 29 mpg in town if I didn't have to make any stops for lights. This is all on a stock AT TRD OR.

It appears that the main explanation for this is that the fuel efficiency is quite miserable when the engine is cold. My guess is that it won't go into to Atkinson cycle while the engine is cold, and the Otto cycle on the engine has relatively low fuel efficiency. As such, the fuel savings appear to be all in staying in the Atkinson cycle as much as possible. This would also explain why the mileage is so much lower when going up hills, driving into the wind, etc., as the engine stays under constant load in these situations and cannot make the transition from Otto to Atkinson. If I had to guess, the Otto cycle efficiency on its own is probably around 10-12 mpg, and the Atkinson cycle is well over 30 mpg.

 

7 mile commute to work each way, all stoplight to stoplight. Not mashing the throttle, Truck is barely up to full operating temp when I get to work.
Average anywhere from 12-14 mpg

 

I stopped paying attention to MPG but have realized it takes a LONG time to increase but very fast to DECREASE the MPG numbers. I drive 19 miles to work and I get 19-20 MPG but if I drive shorted distance the miles driven match the MPG...

 

I stopped paying attention to mpg’s after using the AC. However, I was curious to see what I’ve been averaging this month with AC use included, and not just randomly. Averaging about 12 miles to work, probably not enough for the engine to work it’s magic. That being said, getting out of the canyons in S4, then all city, stop and go. I was surprised and stoked with the average mileage as I’m not being light on the foot either. Doubled up on the 11th.

 

Yeah but according to your picture those dates are winter months when it started getting worse. Mine just went from averaging 20.5mpg to over 22mpgs on my 40 mile round trip daily commute now that it's transitioned to summer blend.

 

I reset mine every tank. This is with a manual. Gotten damn close, but still never broken 20 in 38K miles

 

I would guess the same. When the 3 gen came out, the media consensus was “buy the 6, it has way more HP and almost the same MPGs. As if you could just have the best of both worlds magically...but no. You get 6 cyl MPGs when it feels like a 6 and 4 cyl MPGs when it feels like a 4. Kinda.

 

That would qualify as exclusively city. Some people in here talking about averaging 14 combined all the time in all conditions.

 

Mine about 16.5 avg now. Getting worse with summer gas i guess

 

Describe your weekly commute, area and speeds driven, highway or stop and go, duration and speeds travelled.

 

Looks good to me

 

OP that sucks for you and everyone else getting sh!tty gas mileage. Sounds like something is definitely up.

Everyone else complaining about 16-18 MPG makes me scratch my head. Did you research before you bought? There’s a thread on it every week here.

 

Stock 2017 TRD OR tires.
Let tire pressure drop to cold 31 psi and dropped average mpg to 16/17.

Pumped them back to cold 35 psi got average mpg back up to 19/20.

The correct psi makes a HUGE difference! Give it a try.

 

I run 36 cold which usually means 38 or 39 once the tires warm up and I have a lifetime average of 22.6 over the first 4500 miles.

 

I'm running 40 cold.