Cruise Control Gas Milage 2021

Good point! Still crazy though that my Mpg increased significantly IN Wyoming just by manually Reving and not using cruise

 

My mileage is generally better in the mountains as well. If you think about it you will run the truck a little harder going up one side of a pass or hill and then use a significantly lesser amount of pedal or just coast with no fuel burn down the other side.

 

Expectation is too high. Lower the bar. Eventually you will be happy.

 

I'll second that for some reason I get better mpg at either low 60s or 75mph. At 70 it feels like its struggling and gets worse mpg. At 75 I'm at 2100 rpm engine feels happier with more power then.

 

I’m past the initial shock always had shitty vehicle in the mountains so pulling up to Jackson Hole in the Tacoma eased all my worries

 

Yeah, cruise control in hilly areas suck... You go up a hill and it revs to 3k or 4k.

Wish there was an "Eco-Cruise" mode that linked with the inclinometer so you could lose a couple MPH without killing your MPG.

Got some new tires (Cooper Discoverer ATP II) that have slightly better traction than the stock OEM Goodyears, that combined with the Winter formulation of gas that lowers MPG I only got 19 MPG instead of 21 MPG coming back from Boone/Wilkesboro area. Flipping Winston Salem is hilly.

 

I would much rather have the coopers than extra mpg. I got caught in a terrible storm in Wyoming and my stock tires would NOT have made it through.

My stock tires were Toyo highways.

 

Drafting off of someone setting the pace makes a huge difference.

I was going to mention that as well

 

A big factor I’ve found is the simplest part of the whole equation: cruise control is strictly reactive. It works against gravity at all times. It will slow you down when moving downhill to maintain the setpoint, then try to recover the speed you lose once going uphill.

On the other hand, you and your foot can be proactive. You should speed up a bit going downhill and allow the truck to slow down a bit going uphill.

You can see the road ahead and plan for it, the truck cannot. This is true for any vehicle configuration, so it doesn’t really matter if you have big tires or a lift or whatever. In that case you just have a different nominal mpg which won’t be that of a stock vehicle.

Honorable mention to excessive payload and excessive wind.

 

I've had issues with Toyota's cruise control programming ever since we bought my bride's '16 Camry. I find the same issues with my '21 Taco when using Adaptive or Constant CC. For some unknown reason Toyota's engineers decided that the vehicle needs to IMMEDIATELY get back to the set speed, which often (to me anyway) is the equivalent of flooring the skinny pedal until that speed is reached.
I can get better MPGs without using CC by allowing my speed to vary a bit (+/- 4-5 MPH) depending on conditions. I'll pick up a bit of speed on the downhill and let it slide back below set speed on the uphills. The CC programming doesn't appreciate the MPG advantage to slowly getting back to set speed after a slight uphill stretch - it seems to think it MUST be immediate, resulting in sometimes insane downshifts.
Sometimes I kick it out of CC when I know there's a short uphill stretch and let it slide a few MPHs below my customary set speed. This helps to avoid the crazy downshifts which can really suck up some fuel.

 

Have no idea what’s going on with your cruise milage. I will say 80 mpg will results in terrible gas mileage.
I use adaptive cruise and at 75 mph I get over 21 mpg on the interstate with no huge hills just flat and slight grades. 2.7L access cab stock.

 

I hit the ECT button as soon as I start my truck. This holds the gears a bit longer and prevents that upshift when cruising annoyance.
Wind resistance is a big killer on MPG's too. So when one is following another truck at high speeds, the lead truck may be breaking the wind and causing a drafting experience for the truck following ( Watch Nascar for this).
Wind from different direction, the humidity in the air, temeperature, elevation and road surfaces also play a role in MGPs to a certain degree too.

I've quit watching my mileage. I don't drive enough to worry about the cost. I just watch the distance to empty so I can fill up before I run out.