Had the truck two weeks , it runs better on 89 octane

Truck has 62K on it. im in NJ Well maintained by previous owner and all HiWay miles/ I'll be digging into it in the coming weeks. Maybe it is summer gas https://www.eia.gov/todayinenergy/detail.php?id=11031

 

I came across an interesting video recently regarding the “testing” of different octanes
https://youtu.be/Ro_XYDw9kSA

 

How can one argue with that video.

 

Yep...
The Shell I fill up at has 87E10, 89E10 and 91E0.
The 87 and 89 are around the 'same' price; 91 is $1-2 more, per gallon. I very much doubt they're blending 87 with liquid gold.

 

yes, the facts say the ecu can adjust the timing advance to different grades in octane leading to increased or decreased power

 

Video never once mentioned if he ran into head winds with the lower octane first trip.

 

I've seen this around, but is there any documentation to support this? How does the ecu know you have put higher octane in it?

 

it senses knock then retards timing on lower octane. that's what VVT-i does. it varies the valve timing depending on conditions.

 

My understanding was it mostly adjusted based on map, rpm and throttle position, leaning until you get knock is a bad way to run an engine. Like I said do you have any documentation to support this?

 

I just read through this post because my ‘21 started stuttering when cold and accelerating, my ‘16 did the same thing. I want to note that the manual calls for 87 as a minimum and the Toyota website at one point had in small print that all testing was done using 91. I live with a lot of steep hills and on 87 the engine really knocks on hills. I run 93 most of the time and never have knocking. If I run two tanks of 87 I’ll get occasional knocking under hard acceleration too. However, I don’t notice any power difference between 87 and 93, but likely wouldn’t under normal driving. I notice no MPG difference in the summer, but consistently get 1 MPG better in the winter on 93. It seems to me that 87 would be fine on the flat, but if the engine is under regular heavy load (hills, towing, driving hard) then 87 might not be ideal. As for the stuttering I’m not sure of the cause, but assuming it is just a Tacoma thing.

 

91 RON, not octane.

"87 (Research octane number 91) or higher" Page 572 of my manual for the 17 Tacoma.

6 years and 74k miles later, I still am on Team 89 octane or better though.

 

VVTi is only about cam/valve timing. Ignition timing is a separate system.

 

I run 87 through it from time to time but that’s largely because regular is 85 here. Can’t say I’ve ever felt much difference.

 

I try to use mid grade (usually 87 or 88) when passing through the higher elevations that sell 85 octane.

Other than that, manufacturer recommends 87. So that’s what I use.

One thing I am curious about for those who experience knocking is, what kind of fuel are you using. Is it top tier?

 

Incorrect, there is a point to running 89. Research more and get back with me.

 

You will not hear knock in a modern fuel injection engine. You won't. Knock is aggressively monitored by the computer and it instantly adapts to knock well WELL before it would become audible.

 

I have monitored the engine and between 87, 89, 91 and top their there was no difference in maximum timing per load range on any of the different fuels

In short, you won't get more timing.

I am starting to wonder however if those running high octane also get pure gas (no ethanol). The fuelling on my truck seems to severely limit enrichment and is aggressively lean, and the slightly denser pure gas could help that

 

https://www.tacomaworld.com/threads/maryland-tacomas.198020/page-4212#post-28073036
And in this very thread:
https://www.tacomaworld.com/threads...tter-on-89-octane.668446/page-3#post-28247284

 

I have been using 89 for the last 3 months and I noticed an improvement in the shifting of my transmission. It could be a coincidence since my truck hit 8000 miles. But I can attest that it shifts as smooth as glass now.

 

Could be the truck has a tune on it that is designed to run on the higher octane.