cruise control frustration

it is combination of the cruise logic, and trans logic. cruise wont let it lose more than about a 1/2 mile an hour, and then it is kicking down a gear or 2, or 3, to get you back to speed. the translogic demands the truck get into 6th as soon as possible, even as low as 45 mph... then the cruise, trans dance starts. if I had my way, we could lock out 6th until the truck is over 65 mph, and never shift into 6th below that. the truck for my driving, in auto when driving by foot, seems like it is in the wrong gear (to high of gear). like having a manual trans, or motorcycle in 6th, when you should be in 5th or even forth. you can feel the truck chug along, waiting for more pedal, so it can downshift, or less load, so it can stay in the same gear, or even go higher. I am a light pedal, smooth pedal kinda guy so, maybe, the truck just cant learn it. Ski

 

OP...beast mode on the miles...DAMN!
Ill get to that in about 4 years...LOL.

I dont run long stretches on the highway typically, but Ive always used CC even for short stretches of even like 2-3 miles. Yes, Im lazy. Thats on other vehicles though. This Tacoma CC is just all over the place. Im better off just feeling it with my foot if I want to tamp down and get the best MPGs possible. Id think youd be better doing that as well.

 

Yes it is for comfort and yes it is good for mileage if set at the right speed then you should see some good mileage. I am mostly on highways and I see the difference in mileage compared to commuting. just saying

 

The MPG drops when I use CC on anything but a "prairie-flat" road or highway. Any area where you start up even a somewhat slight climb, it will lose speed and lug before finally downshifting to regain the speed; it will then over-shoot the set speed by 3-4 miles per hour for a bit before adjusting down the throttle to the set speed. Wash/Rinse/Repeat. Using resume does the same thing: Over-revs and overshoots the set speed every time. It's fine on the flats and long slight inclines. It's one of the worst speed controls I have ever had. Most vehicles I have had with cruise could hold the set-speed dead-on and anticipate the throttle position needed to do it: coasting or accelerating, uphill or down. At least two of them had Cruise and fly-by-wire gas pedal and used the ECU to to read and adjust/control the speed: No vacuum servo and cable for the Cruise.

 

It was a lot worse in 2017.

 

I have a aftermarket tune and it did great things to the shifting, just not when I use cruise control. It is horrible as OP stated. Def likes to be in a lower gear. It doesn’t help to be in regular cruise either vs adaptive.

 

Try running in manual shift mode (mt owner here, I assume that is a thing)

I expect it is not so much the speed or cruise but the rigid adherence to a set speed. I would guess that when running without cruise you let the speed vary more.

Point being, max specific power economy isn't always at the lowest rpm, so just because it is running at a higher rpm it can be getting better fuel economy for that POWER level.

 

My 2016 has done this since day one, even with a tune. Either eat the gas or don't use it, that's what it really boils down to.

 

Huh

 

There are free phone apps + ~$30 on adapter and toyota PIDs.
Or count shift and torque converter locks..

 

Can you leave it in 6th gear, with cruise control?

 

This makes perfect sense and I believe it applies to the 5-speed Intelligent Aisin auto transmission in my 2014. It adjusts to the nice sedate cruising on the open highway and responds to adjust for slower/delayed downshifts. Here comes a hill: It now gets behind the curve for the downshift and over-compensates. when the downshift finally comes, the result is over-running the set speed. Downhill, the transmission senses the speed is running up an kicks down to control the speed. Not a big issue since that also kills the cruise control. When I first got my truck I took it on a fishing trip in the White Mountains. Lot of steep, curvy downhills. The transmission started to do its downhill/downshift ballet: every time I touched the brake. My heart jumped thinking I had purchased a truck with a wonky transmission. Nope: Just a smart one.

 

Makes sense: New Generation/first year of new transmission with "learning and growing pains" to deal with, and I'd be will to bet -no- change to the cruise ECU logic to compensate.

 

I lurked in this thread early on, and thought “OP, that’s weird, you should take your truck in.” That was based on my absolute love for the adaptive CC in my truck- that works flawlessly and exceeds my expectations.

Then, I read all the subsequent responses. I guess I got lucky, my CC has been awesome.

 

At that kinda gas mileage and your kind of driving, I’d be looking for a hybrid.

 

Hell, I've been known to use CC on Lake Shore Drive in Chicago? Why? It kept me from getting lots of speeding tickets.

 

@Quien es?

It's really a matter of driving habits and how the applications are utilized. (That can be debated but it's just an opinion)

Everyone has their own habits/quirks about their driving style.

What works well for one may not for another.

Glad it works for you in your truck--it works great for me too!

EDIT: it helps to have a Tune in your truck.

 

You get your best fuel economy with a steady throttle. Cruise Control is exactly the opposite of that. It's constantly accelerating then backing off, accelerating and backing off again, and if you hit a hill or even a headwind, it's going mash how on the gas to maintain your set speed. Another enemy of fuel economy. Add to that that you're driving at nearly 80 mph and it all adds up to lousy mileage. The ONLY time I use cruise is when I'm on flat, level interstate with no headwind or a tailwind, and never, ever, use the idiotic adaptive CC as that's going to add braking into the mix which will also kill gas mileage. Your best fuel economy will always be with no cc and slowing down and keeping a steady foot on the hills even if you're slowing down somewhat by the time you're at the top of the hill. There's nothing wrong with your truck other than not understanding how CC works and how that affects fuel economy.

 

Hmmm, granted most of the cars I've ever owned have had manual transmissions, literally every car I've owned over the last 40 years has gotten its best fuel economy with the CC engaged. Now, before you say I'm a crap driver, I virtually always getter much better fuel economy than advertised per tank, regardless of whether I'm using CC or not, and given I do 99% of my long haul driving with the CC engaged, I suppose it is possible I could get even better if I didn't use it (but I doubt it). One other item of note, as I mentioned above, I have only owned a few cars with automatic transmissions, and to date them a bit, the highest number of gears of any of those automatics is 4, and they all had locking torque converters which were very difficult to provoke into unlocking the TC Clutch. I don't know, maybe that's the difference here, a manual gear box, or an older automatic with a locking torque converter which stays freakin' locked.

Regardless, I would argue it is the rare person, all else being equal (which clearly it is not the case with automatic Tacomas), who can get better mileage without CC being engaged on a long trip.

 

Get a KD Max tune. It will hold 6th in cruise unless you have a steep hill. And better gas mileage. With smoother shifts up and down. You will love the difference.