Finally a fix from Toyota for Stumble condition (TSB 0062-18)

Same here.

 

I am fascinated to understand how octane could impact a transmission issue.

 

My brand new 2019 DCSB OR seems equal to my previous gen3 which had the TBS applied. However I've got a small sample size to compare being less than 500 miles on the OD. Being a bit gun shy, I keep looking for poor shifting, stumbles etc and just haven't seen any issues. But the jury is still out until 3-4 tank fulls. I don't have a OBD reader that will show such settings.

 

The tranny TSB made my tranny shift better but I still had a “miss” feeling at almost all speeds that also felt like a stumble off the line. Premium helped. I think there are definitely two different things going on - the TSB for the crazy shifting and the premium for the miss feeling.

 

I'm not sure what you mean exactly, but my truck has the latest TSB and still needs 93.

 

Same here - not sure my response made sense but I have the TSB (truck shifts well enough for me now) yet feels like it’s missing if I run regular gas.

 

Interesting discussions. I doubt high Octane will fix the tranny issues at low speed, but will try!

 

I’m virtually certain it’ll do nothing for the tranny shifting. My truck simply hates regular. Within miles of putting it in it starts to feel like it’s missing. It feels that way off the line and throughout various other speeds. It’s hard to explain but I needed the TSB AND premium to get mine up to snuff. It’s fine now and if I ever get it out of the shop for whatever the heck corporate is doing for my rear end howling I might actually get to drive it.

 

My 2019 has #8966304B3100 from the factory.

 

Door sticker has 09/18 date

Door sticker has 09/18 date

 

I agree. Higher octane only serves the purpose of reducing the likelihood of detonation. It doesn't add power and doesn't improve the burn. If anything, it robs power at the lower end because it is more burn resistant. Older engines would knock at high rpm when under load which was the indication of needing higher octane. Modern engines will retard timing to compensate. It seems that the assertion is that at low speed that there is some sort of retarding of timing. I would love to hear the explanation of how this would happen at lower speed. Using that same logic these trucks should be choked completely at high RPMs using 87 octane.

 

Let me explain what I’m seeing with my 2017 OR. first I had irregular shifting at 40-50 MPH where it seemed the granny didn’t know what gear to go to so it was hunting for the right gear. That was fixed with T-SB 0062-18.
Now when taking off from a full stop, nothing crazy, just normal street driving, 10-30 MPH, it goes 1st to 2nd at normal time, then a little too soon to 3rd and then quickly to 4th. By then I’m at 1100 RPM and the truck feels like it’s in a gear that’s too high. So a little hit on the gas gets it into 3rd, then in few seconds it goes to 2nd. This happen every time unless I’m constantly pushing to go faster with a higher RPM then I’m in control and not the tranny.
It just seems like this a bad choice of a tranny on this truck.

 

How do you like the pedal commander so far?

 

https://www.ovtuned.com/blogs/news/...-tacoma-transmission-and-how-we-are-fixing-it

Click the link, it should help make sense of the transmission's funkiness.

I've been driving with the TSB for a couple thousand miles now and it really is a MUCH better truck in terms of shifting and predictability, but there's still room for improvement. I've noticed a significant difference in drivability with premium (90 up here) vs 87 octane, and about 1-1.5mpg better for premium too. At current fuel prices, the $0.20 difference is about a wash in terms of overall cost if the mpg holds up too.

 

Interesting changes. Wondering why Toyota never thought of that?? Downside is it probably voids any warranty on the truck.

 

upside is that unless you actually tell Toyota "I have OVTune loaded into my ECU" they would not be able to tell you have it, not even with Techstream. It would be hard for them to deny you warranty work for something they can't prove you have

 

Had this update done.
I really never had an issue with the shifting on my tranny, and I never really had an issue with the responsiveness.
Little lag off the line which I took to be because of the torque curve.

My impression of the update is like someone just poured three cups of coffee down the tank, figuratively speaking.
It drives like a different truck. Much much more peppier/responsive, all bands, all rpm's. Kind of find myself backing off on it more because it really made a difference in the way I usually like to drive it. Quite fun actually now.

Recommend this to all who don't have it.

 

As to why, Toyota and all oems have different targets to meet that the aftermarket gets to ignore. A simple example are octane requirements. Requiring premium would hurt sales for Toyota, whereas the aftermarket can freely give a 91+ only tune.

 

I literally took my truck to the dealer with the OV tune installed they never noticed it. As to why premium works better is because the compression ratio of the truck is 11.8 to 1. That’s pretty high to be running 87 octane. Plus the use of the Atkinson cycle has the timing moving all the time.

 

It’s not the tranny per se, it’s the way it’s programmed.