2019 Cruise Control Gas Mileage is HORRIBLE.

In Canada but experiencing the exact same issues. Recently drove about 800 mile round trip and had average of 10-12mpg. I think the truck shifted into 6th gear maybe twice the entire trip. typically hung out in 4th at 3300rpm and occasionally went into 5th if it was downhill. I am on 285/70/17's and level kit so i know the mileage is gonna take a hit but 10mpg is atrocious. The OVtune will fix this issue you are saying? Without reading the 2000+ pages on the OVtune thread, what kind of numbers for increase HP/torque do we see? I have a 2019 TRD Sport automatic. no exhaust or intake on truck.

 

From my own experiences I've found the problem to be the speed, not the cruise control. 75mph is NOT the "sweet spot", at all. Just for shits, giggles, and curiosity's sake, take a day trip and set the cruise at 65 to compare and contrast. I bet you see a significant increase in MPGs.

 

Should have mentioned i tried adjusting my speed anywhere from 60mph - 80mph and suffered the same issues regardless of speed.

 

Totally agree. As I have mentioned before, I recently drove across the country from CA to VA and NC, and then back to CA. So I had PLENTY of experience with cruise, etc, on the highway! Most of the states across the country along I-40 had the speed limit at 75mph. When I was on cruise at 75mph, my gas mileage was around 21mpg. However, in states or places where the speed limit was 65, my gas mileage went way up to around 28mpg, sometimes actually hitting 30mpg! I was amazed that 10 mph difference in speed made that HUGE of a difference! I would have thought that since Toyota put the 6-speed transmission in there, with 5th & 6th being overdrive gears, that 6th would have been geared to give better highway mpgs at speed. Sometimes I really wonder if Toyota tests these things in real world scenarios or not!

 

I don't think my truck could be in neutral rolling down a hill for 500 miles and get 28 mpg.

 

Hey, I was as surprised as anybody! But when I was cruising between 60-65mph, I had the eco app on just to see what was going on. It was consistently between 25-30mpg, mostly sticking in the middle, which I can pretty much compute to be 28mpg! Make no mistake though, if I came upon some kind of hill where the cruise control 'maintained' the set cruise speed, all of a sudden, instead of cruising along at 1700rpms, averaging 28mpgs, it would downshift and start SCREAMING at 3300rpms, and the gas mileage would go down to around 12mpg! But when I would stop, make no mistake about it, the average mpgs while traveling along the interstate, were always between 26-28mpg. It was then, that I first became happy with my purchase, and selling my trusty 96 tacoma. Believe me, I DID have doubts at first, because of the stupid "learning" transmission, during the first 2000 miles or so. But I really think it began to get better, when I went over 6700 miles during my trip. Ever since then, I have been pretty stoked about the mpgs, all things considered, since it IS a 6-cylinder, much bigger truck, and comfortable as all get-out. yeah, I think I did ok in buying this truck, although I do HATE the interior color! Believe me, I am working on modifying that, as I write this! Stay tuned for updates!

 

The sweet spot on my 19 OR is 70mph which yields me about 21-22mpg. Anything over that it drops off about 3-4mpg.

Shifting improved dramatically once I got about 4k miles on it.

 

I have about 4500 miles on my 2019 V6 auto 4x4, and I have the same issue using radar cruise control - I just stopped using it

 

I drove from KY to ID and back in October 2018 and found the "sweet spot" to be the US and State highways where my speed was 55-65 or so. 70mpg on the Interstate dropped it to a still-acceptable level. States with no interstate speed limit killed my MPGs. lol

 

Roger that. At "normal" interstate speeds (70ish) I got 19 or 20 MPGs. On US highways/backroads doing 55-65mph I got 22-23 MPGs. On interstates Out West with the absurdly high speed limits (doing 80-90mph) my mileage plummeted.

 

Very interesting results. I use adaptive regularly on my drive to work, usually set at 70-72 and I avg 20-21mpg. However I drive to the hill country for hunting season and the speed limit is 75 in a lot of places. Setting to 75 I get around 19. I've seen as low as 17 when I had a strong headwind. One thing to note, I can squeeze more mpgs by not using cruise, but it hardly seems worth the fuss most of the time. In the summer months I was seeing 22-24mpg on the morning commute. Also, if I take the interstate to Austin and avoid the back roads, I can get 20-22 on cruise. You're 13.5 seems really low, but I've seen a lot of people complain about mileage in these trucks and they seem to avg lower then me. Hills definitely kill you mileage and mine will downshift a lot when going through any hills. I always run with ETC ON and have found this gets me the best results. Sometimes in the hills I'll select S5 and ETC, but honestly results haven't been conclusive that this gets me any better mileage in the hills. I'm in doublecab short bed TRD OR 4wd. I do wish I got better mpgs being in a midsize, but coming from a JKU, I am so much happier with my mpg.

 

You are correct about the 65 mph setting. But, it's because the transmission doesn't struggle as much to maintain the lower speed. And shifts back to 6th gear a lot sooner than trying to maintain a higher speed. You "can" get decent MPG @ 75 mph if you make a conscience effort to keep the transmission in 6th gear.

I've noticed the same thing when using CC. Driving without CC, I can usually climb the hills in my area and still keep the transmission in 6th gear. I wish the transmission had an Eco Mode that would keep it from down-shifting as much while in CC.

 

I'm glad this issue isnt limited to me. I thought it was because I had the 2.7 I4 and had oversized the tires a bit (265/75/16's).

I dont do a lot of interstate driving (the only time I really use CC anyways) but it sounds like I'm gonna be looking into a transmission control upgrade if I start doing more road trips. Stupid to have 6th gear and not use it.

 

Same for me on my 2018 Sport 4x4. Highway at 73 and back 20lane paved roads at 55 nets me 20+ if I'm not doing any city driving for the week.

@Ariesgtturbo
Pardon if I missed this, but what size tires, type, and PSI are you running at? Some of that might be coming into play. Another thing to look at is to see if TSB 62-18 is applied to your engine's computer. I had a drastic improvement when I convinced the dealer to apply it to mine.

 

How many miles do you have on your 2020? If it's a 2020 I'm thinking you haven't even gone past the break in period or just barely. My mileage wasnt that great when I first bought the truck but after a few thousand miles and a few tanks of gas, the gas mileage got better.

 

I got mine to average 28 on a 200 mile trip. I didn't go above 65 bc I was extremely tired for the whole trip

 

I have a 19 with 9k on it. Still is awful.

 

I have a 19 sr5 with 265 75 16 wildpeaks and my cruise works just fine. Of course it downshifts going up hills it's supposed to. I still get 19/20 with cruise at 75.

If peope are sick of down shifts go get a car w a cvt and stop complaining.

 

Well that sucks lol. After my break in period i averaged anywhere from 20 to 21 mpg highway. After lift and putting on 285's i'm getting anywhere from 18-19 mpg highway.
edit- misread your "it's 2020" and thought you said "it's a 2020".