Experience with 2 tanks of premium

stiles_s

New member
I know… been beaten to death. The 4r’s ecu doesn’t take advantage of premium fuel so it is a waste of money.

On a whim I decided to try a tank. My biggest frustration with the truck is that I have to downshift to make it up a slight grade on the highway heading to work. Drive it every day.

I swear the truck feels like it has more low end torque with premium. Less downshifting, same roads same speed.

And the ecu reported gas mileage is also at least 1mog better.

My rational brain thinks I am imagining things. Can’t be happening based on what we have been told about the ecu.

YMMV


Sent from my iPhone using Tapatalk
 
Register to hide this ad
My 2019 runs noticeably better with 93 octain, and when I'm out west at altitude loaded with gear the difference between 87 and 91 octain are very noticeable.
 
I know… been beaten to death. The 4r’s ecu doesn’t take advantage of premium fuel so it is a waste of money.

On a whim I decided to try a tank. My biggest frustration with the truck is that I have to downshift to make it up a slight grade on the highway heading to work. Drive it every day.

I swear the truck feels like it has more low end torque with premium. Less downshifting, same roads same speed.

And the ecu reported gas mileage is also at least 1mog better.

My rational brain thinks I am imagining things. Can’t be happening based on what we have been told about the ecu.

YMMV


Sent from my iPhone using Tapatalk

should try diesel next time
 
Higher octane premium fuel reduces the annoying 'tinging' sound from my engine. Corn additives....sigh.
 
How does using cruise control change the fact it needed to downshift to maintain 60/65mph up a grade? Plus it being dangerous in this scenario (heavy traffic)


Sent from my iPhone using Tapatalk

Using CC reduces the chances that you’re subconsciously manipulating the throttle to avoid downshift.
There’s a spot that I often use to see if it will downshift or not along Hwy 1. Usually it’s something like a small tailwind or a few mphs higher and no downshift.
Unfortunately I found no real improvement from the available 91 octane premium.
 
Using CC reduces the chances that you’re subconsciously manipulating the throttle to avoid downshift.
There’s a spot that I often use to see if it will downshift or not along Hwy 1. Usually it’s something like a small tailwind or a few mphs higher and no downshift.
Unfortunately I found no real improvement from the available 91 octane premium.


I could see how use of cruise control can offer a higher consistency of given inputs if you are A/B testing downshift propensity across different octanes of fuel.

On the flip side, use of CC will trigger a downshift if you’re about to lose even 1 MPH of speed ascending a grade, instead of letting it slip to 63 MPH and stay in 5th.

I don’t think there’s a “right” answer as to what “should” happen as you ascend a grade - personally I like to test how long it can continue lugging uphill before downshifting.

So long as we are keeping an eye on temperatures, getting fluid changes, and not throwing any codes…

Does gear hunting seem worse in 4Runners or Tacomas with the 6 speed? IIRC 5th is 0.75 and [if there is a] 6th [it] is a 0.66 reduction.


Sent from my iPhone using Tapatalk
 
Drivability is improved very slightly. Mpg? No difference. I’d rather put my money on premium fuel than an intake system.
 
I could see how use of cruise control can offer a higher consistency of given inputs if you are A/B testing downshift propensity across different octanes of fuel.

On the flip side, use of CC will trigger a downshift if you’re about to lose even 1 MPH of speed ascending a grade, instead of letting it slip to 63 MPH and stay in 5th.

I don’t think there’s a “right” answer as to what “should” happen as you ascend a grade - personally I like to test how long it can continue lugging uphill before downshifting.

So long as we are keeping an eye on temperatures, getting fluid changes, and not throwing any codes…

Does gear hunting seem worse in 4Runners or Tacomas with the 6 speed? IIRC 5th is 0.75 and [if there is a] 6th [it] is a 0.66 reduction.


Sent from my iPhone using Tapatalk

Good question. Our RAV4 has a 6 speed and up/downshifting is barely noticeable in comparison to the 4R.
Lugging my 4R transmission in 5th on a grade will quickly bump ATF temps over 200°
 
Good question. Our RAV4 has a 6 speed and up/downshifting is barely noticeable in comparison to the 4R.
Lugging my 4R transmission in 5th on a grade will quickly bump ATF temps over 200°


I will see if my scan tool can monitor the same, and report back!


Sent from my iPhone using Tapatalk
 
A good explanation here.
https://www.youtube.com/watch?v=1OFV8gpxAxI&feature=youtu.be
The difference in octane is how fast the fuel burns. At the tech school I attended long, long, long, long ago, had a demonstration. A long clear tube, 4-5 feet had anatomized drop or 2 of different octane gas put in it. When ignited you could watch the flame travel the length of the tube. The higher the octane, the slower it burned.

Sent from my SM-S908U using Tapatalk
 
I rather just save my money

I hear you. Normally I'd agree, but for me there's a big difference between the truck feeling so gutless it can't maintain 60mph in top gear up a slight grade vs having just enough of a boost in low end torque to pull it off. YMMV
 
I hear you. Normally I'd agree, but for me there's a big difference between the truck feeling so gutless it can't maintain 60mph in top gear up a slight grade vs having just enough of a boost in low end torque to pull it off. YMMV

Ok I have a confession, I re-geared

But I won’t pay more for premium gas lol
 
Last edited:

Members online

Forum statistics

Threads
278,316
Messages
3,554,111
Members
248,016
Latest member
Advally Service

Trending content

Back
Top