2019 Cruise Control Gas Mileage is HORRIBLE.

Went on a 1200+ mile road trip over the holiday. One of the biggest reasons I chose to upgrade to a 2019 was the available safety features, and that amazing adaptive cruise control.

But when I used my cruise control, set at 75mph, I would be getting an average of 13.5mpg. Its insane. I also noticed that if I a set at 75mph, and I am down to 73mph on a slight incline, the trans would shift down (to 4th gear?), running at about 3300rpm. Once I reached the 75mph, it would stay in the same gear, running 3300rpm. the only time it would shift up would be if I was on a decline. But it would then jump back into a lower gear if it fell behind.

I tried setting it in the 72-73mph, thinking maybe I was just in a strange shift bracket... nothing changed.

If I turned cruise control off, and just managed my speed manually, I would be in the 17.5mpg. But I also noticed that I would stay in 5th most of the time, and once I reached my desired speed, I could let off the throttle slightly, and get it to shift into 6th, running at about 1700rpm.

Anyway, has anyone experienced this before, and was there a solution? Is OVTune something that allows you to change the shift points, for either better fuel economy, or more performance (if wanted)?

I have another big road trip planned in march, and I would like to see what solutions are available before I head out on that one as well.

Thanks everyone!

 

I put my truck in 6th gear, hit the cruise at 79mph and never come out. Typically get about 19mpg. Obviously, it’s a manual though.

A lot of people with autos have luck leaving it in s-mode as you’ll get less shifts this way.
An OVTune would also help your dilemma quite a lot.

 

I've noticed that radar cruise induces more gear changes, which will reduce your MPGs. If its not a busy highway and I am on there for a while I switch to just using normal cruise control and have much better luck. I know its silly, but check your tire pressure. Low tire pressure can destroy your mileage.

 

Here comes the newbie in me...

Wait, I can turn the adaptive cruise control off, just making it regular cruise control?

I am a little pissed that the dealership didnt walk me through the features it has.

 

I will try the s-mode and test it out on the highway. Great advice! Thank you.

 

Yeah its kind of hidden. Instead of just pressing the cruise control button to turn it on, hold it for like 2-3 seconds and you'll see the icon change in the dash.

 

Great to know! Thank you!

 

Unfortunately this is all normal for a 3rd Gen. Cruise control is absolute trash in these trucks especially in terrain with hills/mtns. I never use mine as its so bad & like you have seen kills mpg.

 

yea, I was in the mountains of Kentucky and Tennessee. But now I know. Hoping that with a couple smalls changes, my trip to Texas will be flat enough where I wont see many issues.

 

You're welcome. In my non scientific testing it seems to hold gears much better, but you lose the radar functionality obliviously. So you have to decide which you'd rather use at which time. But if its a road trip and a lot of highway miles I tend to use the non-radar cruise as there is no use for it with little traffic.

 

Apples and Oranges sort of, but mine in the 2016 is fine. Turn it on, and leave it. always 18-20 MPG.

G.

 

Did 500 miles yesterday over mountain terrain and averaged 20.1 with cruise control on most of the time. I did notice on an incline the cruise control speed would drop 1-2 miles per hour than what I set it at. Also, during curves, the cruise control radar would sometime detect another car in the next lane and slow down the car with no one in front of me which was annoying. My speed was set 80-85mph and have a 2020 TRD sport for reference.

I do agree that with the cruise controlled engaged the truck seemed to stay in a lower gear vs. when driving without CC and letting off the accelerator and the car would go into a higher gear as you mentioned. However, it didn't seem to have a huge impact on my MPG.

 

Have you tried higher octane?

 

I tried higher octane for a few fill ups and notice no change in MPG or drive ability.

 

You must live were there is no hills/mtns. My biggest complaint in this truck is the cruise control, it is the worst I have ever experienced in any vehicle.

 

Cruise control was never meant to optimize mpgs. This is why you coast down hill and slow down going up to hills for optimum mpgs. I average 18-19mpgs (17-18 winter) in my truck with armor all around, lift and 285s because I never use cruise control.

 

Any highway driving when speed is above 60 my mpg takes a nose dive. However, my 2016 had the same issue where when using cruise control my stock truck would never stay in 6th gear. Even driving across flat Nebraska at 75 mph the truck refused to stay in the big gear in cruise control. I found I gained a couple mpg not using cruise control. I would get really frustrated with my truck during highway drives. This truck is my first automatic transmission vehicle after years of driving manuals. All I could think was, “If these trucks have smart transmissions, mine would be in the special ed class”

And this was all after I had 2 of the transmission tsbs performed on my truck.

My saving grace was OVTune. My truck drives intelligently now. 6th gear holds in cruise control helping my mpg equal what I get when I simply use the right foot. I no longer get frustrated with the truck driving highways and completely love the truck now. Good luck!

 

I use cruise control all the time without issue, though I rarely drive 75

 

I have not. I am always putting in mid-grade, which is 89-Octane. I have seen 91 ad 93. I will also try those and see if there is a difference.

 

Have you tried a ridge line?