Compression of our motor and octane

I don’t fully understand although work gives me 89-90 octane @ 100% free ethanol “off-road fuel” commercial grade

 

it's quite a big difference with octanes with the 2.7.

 

"Offroad fuel"?
Might want to add fuel cleaner every now and then, if it lacks detergents.

 

Is premium fuel in high demand where you typically fill up? Lots of dentists, lawyers, and doctors filling up their fancy German sedans and super cars with premium? Or does no one pump premium around you?

 

Is this the reason that the engine struggles more at load + low revs & light throttle, but improves dramatically with load + low revs & added throttle (i.e more load)?
- Or is that simply a matter of Fuel supply?

 

CR and ignition advance both make the torque that we like, but that would be an oversimplified view, IMO. Like you know, every system and feature is interdependent. A basic tune that rebalances those seems to give us the low load power that is missing on the Stock tune while not hurting the MPGs.

I'm not really sure what Toyota was chasing, but they really messed it up.

The one really big thing to note is that over a certain amount of throttle and load, you get into Open Loop fueling. This can be monitored on the Torque app very easily. Everything seems to run very well in OL, like you noted. It is kinda hard to screw up since it is not dependent on a senor feedback loop as much as Closed Loops is. It just dumps in a programmed amount of fuel.

My bike has a simple OL EFI that is easy to work with and is just wonderful when properly setup. That said, the stock config sucked as bad as the Taco did down low. Even there, MPGs never suffered with the breathing and fueling mods.


So with that long winded rambling, the fake Atkinson cycle is somewhat to blame, but not the entire cause, IMO.

 

All I can comment, I use it in my snowmobile during the winter. No issue for my 600 that has a few tricks done to it....runs well in my boat too, but that engine is bone stock. Premium just runs like crap in my truck. I live right in the heart of the wine, and cheese crew. Lots of Audi Quattros, Beemer suv's, and Lexus RX 350's around the lake here. I'm more on the the poor side here.

 

When I had toyota 4x4 22re trucks, they'd run no different whether 87 or 93 was used, a pooch was a pooch.

 

those didn't have the newer algorithms these trucks run on that constantly advance the timing until knock. No dual-vvti either.

 

These modern engines, with the ECU constantly adjusting the timing, would have to benefit from higher octane.

 

I was checking stats on Highlander Hybrid amazing 6000 HP and 14 compression ratio. Must be Red Bull edition

 

Maybe some do, depending how they're ecu is mapped, but I can't see it with my truck. It already runs extremely well on 87. Seems anything over 89 is the tipping point for it running worse. It would piss a buddy of mine off to no end, seeing how my truck ran compared to his, that was a year older.

 

There has been many dyno tests with the 3.5 since it was introduced to the Tacoma in 2016. They have all done better with higher octane. Even Toyotas tests were done using 91 octane. To be fair though, I typically use 87 octane myself. My truck seems to run fine with it too. When I plan trips pulling my camper I'll be using premium though, I want anything extra I can get.

 

I think it’s just commercial stuff

 

yup, just like so many other cars in the toyota/lexus lineup, this engine can survive on 87 but it thrives on 91/93. When I switched to 93 the biggest thing I noticed was how much better (not as good as the 4.0 tho) it held 70-75 on the highway. That was always the biggest thing for me with this truck. I am sure tune would help but I just havent gotten around to it. MPG went up a tiny bit but not worth the offset.

 

I heard the same if you drop a bunch of unscented moth balls in the fuel tank.

 

"unscented?" You know what moth balls smell like??!!

 

My 2021 offroad MT never had any troubles pulling in 6th at 70-75mph. I was actually quite happy with it there. At lower RPM's though I really missed the torque of my 2013 4.0 MT. I was able to work around most of it because of the MT. Pulling my camper I couldn't work around it anymore. That's what caused me to get the OTT tune. It made a big difference. At lower RPM it pulls similar to my 4.0 now. I would've never thought the 3.5 was even capable of this, but it is.

 

The standard moth balls stink. They sell types that smell nice, but imo don't work as well.

 

I can't complain about not having enough low end in my 3.5 auto. My 2020 has decent low end torque. I can't understand all the complaints some have on this.