Disappointed with power

Just bought this 2017 SR5 and wondering why when going up incline (and not very steep at all) the transmission shifts back and forth many many times and it seems like it is unable to keep set speed. If this is normal then I can’t imagine trying to pull anything. Anybody?

 

What motor and how many miles?

 

Is it on 37's and stock gearing? More details would help.

 

This will fix it.

 

Normal

 

Not Normal

We need some more information. Hows your maintenance on it? You should easily be able to accelerate up any incline. Even at highway speeds. Yeah it might downshift on you some but once you're in a low enough gear, she'll eat.

 

Put the transmission in tow mode and report back.

I run both of mine in tow mode 100% of the time.

 

Need more details. Do you have a 5.7L or 4.6L? Miles? Tire size? Were you towing? What was the incline and distance you observed this at? Depending on the grade and elevation I experience this also.

Remember, elevation saps your power.

You could need anything from a new air filter, plugs, or fluids flush. Or it's normal due to the grade and elevation.

A supercharger would probably solve it and fix a permanent smile on your face.

 

4.6L , 40,000 miles. Left it at the dealer this morning. Not sure on tire size, nothing crazy. Does not have a tow mode.

 

Not meaning this in a bad way... But, are you being a granny with it? Push the pedal down and get the engine to 3k+ RPM. These pigs are too heavy, especially with the 4.6, to lug around the low rpms.

It will eat gas... Cost of doing business...

You can also try S-mode to select the top gear.

 

I would second S-mode, since the transmission will hunt for gears on any type of incline. I get annoyed and drop it to 3rd gear and 4th gear, depending on how much incline is left.

 

Try the 5.7 next time. That extra .75” of stroke gives you almost 100hp.

 

Reset the transmission adaptive learning? lol.

 

yes this is it, 5.7 ftw!

 

For sure. Can’t believe it was so popular, big mistake

 

Just some friendly ribbing from the 5.7 crowd. The 4.6 is a good engine that makes good power. My buddy had a 4.6 tundra that he used for years to pull his construction trailer, often weight 7k lbs up a 10% grade at around 6000' elevation. It's actually one of the reasons I bought my 5.7 tundra, so don't feel like you made a mistake.

As a real answer to your original question, if you are using cruise control, depending on the hill and your drive mode, shifting up and down a lot doesn't have much to do with power, but with being in the power band. The transmission nor the vehicle can predict what the road looks like ahead of you, it can only guess at what lay ahead and react to what it is seeing at the moment via load and vehicle pitch/attitude/speed. If it's pitched nose up, losing speed, and high load for example, it assumes you are on a hill and will add throttle until load exceeds ~93%, then downshift a gear and repeat until it's happy with the load and speed. Unfortunately, if you have lost speed, it will want to gain that speed back, requiring even more load and more gear. Once reached, it will see low load and try to shift up a gear until the load is heavy but not excessive.

Vehicles run most efficiently at high load with low RPM, so in order to be more fuel efficient, the gearing and shift logic are programs such that cruising speed is rarely in the power band, but rather just close enough to produce that high load, low RPM, fuel efficient operation. Low RPM also produces less wear and tear on the vehicle and driver, as well as less incurring less frequent servicing.

Some earlier model tundras had more aggressive throttle and cruise settings, which led some to complain of the exact opposite - the vehicle downshifting immediately on hills and not upshifting for a while after the hill had passed. Again, the vehicle doesn't do a good job of predicting the road ahead, so the vehicle was programmed to be a little more aggressive and keep the vehicle in the powerband for longer to assure consistent speed and power. Folks complained that the tundra wasn't fuel efficient and that the throttle and cruise were too aggressive, so in later models that neutered it to some degree. You are seeing the result of that, unfortunately.

The fix is easy. Your motor makes plenty of power to conquer hills and pull trailers - even pull trailers up hills! The solution is driver input. You, as the captain of your vessel, can command more power with tips of your toes, or a downshift with the flick of a finger. You are inherently better at reading the road ahead with the eyes in your head than letting a blind computer predict it from what road has already passed. So command more power before reaching the throws of gravity straining to restrain you; drop down a gear with gearshift before the motor lugs in languish. Hold that gear until you hear the thunderous shout of freedom from the torrential tailpipe, proclaiming to the world that you have conquered the monumental mountain in a momentous mockery of the typical malignant mediocrity of modern motorists relying on their overdrive overloads!!

You can also get a tune from a trusted vendor to kinda do that for you...

 

It is not luck of power, it is ECU tuned to keep MPG at least double-digit. Even 4.6 has enough guts to spin rear wheels on your incline. Be more aggressive with throttle input, move it quicker, ECU looks for how fast the pedal moves.

 

Very eloquent answer.

 

Thanks fellows! Very helpful

 

I ONLY drive my 2018 in S-mode. Manually selecting the gear (and RPM) is the only way to go, no hunting.

Dan

 

Transmission hunting while going uphill is not normal or desirable. A second opinion from a similarly outfitted Tundra would be a good thing if that can be arranged. Maybe it is normal?? Most of the responses seem to elude to operational issues or it being a 4.6, maybe, but maybe not. The vehicle is a 2017 which only has 40000 miles on it. So it was not driven much or on short trips. Short trips are not great cause your fluids may not reach operating temperature. My suggestion is, in this order, Disconnect the battery to reset the system leave it disconnected for about 30 seconds and step on the brakes while it is disconnected. Reconnect and drive and see what happens. If no change, then replace the transmission fluid see if that helps. After that you may need a good shop to give you an opinion.

 

how do you do that??

 

Microsoft style

 

same

 

my last tundra was the 4.6, a 2014. Keep it in S-mode to stop the gear hunting. The 4.6 is just as solid as the 5.7, you've got a good machine

 

Great in-depth response
Learn something from this as well

 

Disconnect battery for at least 30 minutes.