To Tune or Not to Tune (KMeeg said nay)

Well I initially was about to get a Tune and see what it can do. Then I changed my mind and canceled the appointment. Just sharing on this thread if it has any value to anyone.

I trust this thread will get lot of hate just like my lift thread , but don't really care and it is what I believe. (As for the lifts KMeeg's 4runners need a lift + plastic trimming to clear bigger tires. He tried with just trimming and didn't work.). It's OK to receive hate comments, it's the internet, not family.

Back to tunes;
Here's some reason's why I canceled my tune appointment. To keep it short, long term reliability.

 

Sir,
We should do a gofund me page and get you a tune so you can appreciate the difference. You have playing it so safe all along, why?

 

Over concerned scary guy about reliability
It would be pathetic if still I get problems even after lot of care and playing safe.

 

you should get the OTT tune
its as refined as an older Toyota
The current models are squash boxes of garbage, the engine tuning is whack and the engine screams all the time as the trans shifts and hunts for gears. I think the modern vehicles tuning is looking at load entirely too much and downshifting as the load increases which is good, but it gets way too aggressive and wont let the engine lug down at all. An older vehicle would hit a big hill on the highway at speed and if you dont change throttle input you might lose 3-4-5mph as you climb the hill. This lugs the engine down slightly but you only lose 100-200rpm and once things plane out over the hill you quickly get your couple of mph back. The older vehicles had no issue with this, its not uncommon for my 2008 to lose a few hundred RPM and quite a few mph on a big climb at speed on the highway and never blink an eye. Now they wont let the engine lug down at all, if the load gets above 80% the trans downshifts and rpm climbs. You cant hit a hill on the highway and hold steady throttle and the trans stay in gear. As soon as the load increases, before you even see it lose 1mph, the trans downshifts and engine races.

Personally i think this is likely multi-part. I think its a long term gimmick to help make the trans last longer. Lugging the trans at 100% load on a hill climb will inevitably get the trans hotter and potentially hurt the trans long term BUT older vehicles had no issue with this. I also think this is probably CAFE, something about fuel mileage. An engine lugging down likely isnt moving air fast enough or efficiently enough to burn properly so they would rather you have much higher RPM, more air flow, in order to change how efficient the engine burns.

My 2005 tundra will lug down without downshifting
My 2008 tacoma would lug down without downshifting
My 2008 4runner will lug down without downshifting
My 2012 4runner will lug down without downshifting
My buddies 2016 4runner is definitely different from my 08 and 12 and hunts
My buddies 2022 4runner is definitely different from my buddies 2016 and hunts way more
My wifes 2023 was absolutely pathetic when we got it. You set the cruise control on flat ground in southern arizona and the freaking trans would downshift and hunt for gears on the highway for no freaking reason. The cruise was useless, it would never stay in overdrive. Even using throttle pedal, if you hit a hill on the highway and you scrub -1mph the trans downshifts and engine races. It doesnt matter if you anticipate the hill and slightly tip into the throttle to maintain speed, or if you just hold a set throttle position, if the speed decreases, its downshifting.
This seems like its trans tuning, but its actually in the ECU and its load based. Once the load increases, the ECU says downshift. The OTT pretty much eliminated this and turned the 2023 into how my 2008 drives which honestly drives the best out of all of my recent Toyotas. My 2008 4runner is one of the best tuned out of the box of anything i have driven. The power is great, the engine runs great, the trans tuning / ecu tuning are seamless and you never notice it doing anything out of the ordinary or whacky. I have driven it 260,000+ miles and i love how it drives and everything it does.

I think somewhere along the 2016 range is when Toyota started changing how they were tuned and the further the 5th gens got up in the years, the worse it got. I didnt get the tune for power, or performance, or 0-60 times, i got it to help the 2023 feel more like a normal vehicle and it did that wonderfully.

 

Awesome info. Thanks for sharing.

OTT tune offering support for AGM batteries was also a very nice feature when I looked at it y'day.

 

My 2c.

Tuning for NA engine is a low-risk low-reward proposition. There isn't much that can be done for engine performance. You can tune it for premium, gaining a small performance bump. About the only way to drastically mess this up would involve increasing rev-limiter. Most tunes of this nature would just remap your throttle to make it feel faster, but not actually be faster.

The above is true for 5th Gen engine, however the added wrinkle is shifting points/gear hunting. If it bothers you, it can be tuned out.

Tuning for turbo engine is a high-risk high-reward proposition. You can get drastic power increase at a cost of risking detonations and grenading your engine. Even if nothing catastrophically goes wrong, it is also very easy to create various heat-related issues that translate into decreased durability and increased need for more frequent maintenance. I'd recommend against tuning turbo engines unless you also upgrading your cooling.

Last but not least, any engine tune will void your drivetrain warranty. Dealers are trained to look for tunes as part of major warranty claim investigation, so keep that risk in mind.

 

If there was a bad case or several users complaining about how a tune messed up their 4R, we would have heard it loud and clear from all different angles. And even if there was a bad case, it would still be an outlier compared to the positive acceptance of the wider population getting these tunes. Remember that the tunes are tweaks here and there, they are not drastically changes else the tuners themselves would get in trouble too. You have to dig a little deeper as to why the tuners started their offering which in essence will explain why the OEM settings are conservative (in many instances, emissions related and MPG specs).

 

You're looking at information for Tacomas. The tune can increase the alternator charging voltage only if the PCM controls it, like in 3rd gen Tacomas. The tune can't do it with 5th gen 4R. However, the GM diode mod is cheap enough. Run the diode in series with the existing fuse using two fuse taps to retain the fuse protection.

 

My take:

Why would Toyota engineers (which pride themselves for reliability) not give us an ECU tuned that makes the vehicle with the best power delivery for an engine they have years of experience with?

2 options: reliability and/or environmental constraints (CAFE)

if it's only for environmental BS, then it would be safe to assume reliability is not an issue. But it would be nice to know the real reason.

with that said, even though the risk exists even with a reputable tune, it seems fairly low.

Personally I intend to wait on my truck to be out of warranty, just in case something happens and dealership blames the tune even if not the culprit

 

Maybe I am missing the point of why to do any of this and am not educated enough as to why.

But off the cuff I think of the old phrase if ain’t broke don’t fix it.

 

Exact reason why I canceled the tune. I don't have a problem with the way mine drives even with larger tires and extra armor. The only thing I'm not a fan is the down shifting on a hill when I'm on cruise control. I'm OK not to use cruise control and let the vehicle slow down a little on a hill. So in my situation best is to keep it stock.

 

My 2008 has the same 4.0 1GR-FE that we also have in the 5th gens and the numbers some of them are cranking out is impressive. There are tons of them at 300,000+ miles and running like a champ and have never cracked a single cover off the engine.
My 2008 is CONSIDERABLY stronger than my 2012 and 2023 and all my buddies current 5th gen 4Rs. The engine tuning is totally different, its more crisp, its so much stronger, its so much faster, and mine has 270,000 miles on crappy corn water fuel and runs like a sewing machine. We are in a hilly part of the world and have big rolling hills on the interstate and i drive about 15 miles of interstate every day to work. My 2008 is so simple and easy, i put my foot on the throttle and hold it at a specific percentage and my vehicle runs like its on cruise control. I hit a hill on the highway and you dont even hear it lug down, it doesnt scrub mph, it stays right at 70mph just like it was on flat ground. My 2012 is so much weaker, loses so much MPH on a big hill climb on the highway, its so weak and slushy and has nowhere near the pep in its step as the 2008. That same hill that my 2008 doesnt lose any RPM, my 2012 will lose 6-7mph consistently. My wifes 2023 was watered down even more than the 2023 but the tuning was different. It wont let it lose MPH on the highway on a hill climb, it instantly downshifts two gears and redlines the engine. I dont think the tuning changes in the 5th gens was done for reliability, it think its been getting tweaked over the past 10 years to meet emissions and CAFE guidelines.

The OTT tune on my 2023 made it run just as strong as the 2008, and the crispness and drivability are so much better.