What octane gas do you use for your Tundra?

COPIED FROM ANOTHER THREAD, BUT THIS THREAD APPEARS TO BE MORE VALUABLE.

I was scouring the forum and this fit the bill without starting a new thread. I pull my Toyhauler (6600lb empty) regularly; in-state trips, 600 mile trip this past weekend, and 1900 miles last month. I have always run 87 octane, towing or not. I was (until today) a firm believer in "just run the minimum octane the manufacturer recommends".

The trip:
-Beaufort NC- Mount Pleasant SC (round trip)
-Same cargo each way, same weight, same toys, no water or waste in any tank.
-Same route, same weather, same driving conditions.
-I try to maintain 65-68 mph, seems to be where the Tundra is happiest towing.
-Tow haul On, manual shift mode 5.
-Trip down 87 octane, 10% ethanol. 7.8MPG
-Return trip, 89 Non-ethanol 1st stop, 89 10% ethanol 2nd stop. 8.5MPG


Much more than an MPG observation:
-The truck likes to hunt for gears when pulling, obvious and documented. The slightest movement of the gas pedal when cruising between 65-68 will downshift from 5th to 4th. Asking the truck to accelerate at an increase of more than 1mph per mile will always be returned with a downshift to 3rd.
-The trip to SC was normal, truck would cruise in 5th for a while, then 4th for a while, with bursts of 3rd thrown in whenever it wanted to go there. This was all on 87 octane fuel.
-The return trip was nothing short of amazing, 89 octane with one stop being non-ethanol. Gas light was on when I filled up before we returned home this morning. I based my observation on the fact that I was rolling along in 5th gear for an abnormally long time without a down shift. The reduction in shifting from 5th to 4th was unbelievable. The engine was completely content making decent power under 2500. I was humming along in 5th gear TC locked for the entire length of SC31 around Myrtle. I started to play around with the throttle a little, applying throttle to encourage a downshift. The truck was able to accelerate, slowly, in 5th gear without calling for a downshift. If I applied more throttle it would still induce a downshift to 4th. The truck only reached 3rd on the causeways/bridges, never under normal cruising/accelerating conditions.
-I filled up with 89 in SC because it was non-ethanol available at the station. I filled up with 89 for the 2nd tank just to confirm what I was feeling.

Questions:
-Anyone else out there notice something similar?

-Anyone out there with tuning knowledge on the Tundra? Is the Tundra able to real-time adjust it's timing and shift logic to mitigate detonation under different loads while running different octane fuels @dirtydeeds ? This is the only way I could understand what I imagine was happening. The truck realized, with 89 octane fuel, it was not detonating in a Low RPM/High Load situation and just kept chugging along.

To sum it up. The truck towed with less effort and shifted much less running 89 octane fuel. I directly attribute this to ECM making on the fly decisions to mitigate knock, but with the increase in octane it did not feel the need to keep the truck at a higher RPM under mild load conditions.

 

I haven't gone in a long run yet with the truck as I've only have driven it for 2k miles. You should try 91 or 93 now and see if that makes an even bigger difference. According to DAP 93 should help even more. I haven't tried 89 as I am content driving around with 93.

 

Does e85 run clean, I have herd the gas mileage is really bad- is that true

 

I just got back from vacation to Pensacola Florida mpg 18.5 running 87 octane truck ran great, few times had to get on it to pass (love that power when needed) at home city/highway driving with 87 octane avg 13-15 mpg

 

I've pumped 87 twice and 91 twice. Truck only has about 2,000 miles, hence 4 fill ups.

Seems to get better gas mileage with 91, but it may be a placebo effect. I've averaged about 15mpg combined.

 

What do you mean by placebo effect? Either you have better mpg or you don't. It is not like you are comparing if you are getting more power now than before. Just saying

 

In terms of I may be driving smoother and less aggressively. Placebo effect probably wasn’t the best term to use. Lol.

 

I noticed on my regular driving around town bs, about 50/50 interstate and city streets(no real heavy stop/go), I get 14mpg with my 2011 4wd, 4.6 V8. That's if I drive kind of gentle. Drive kind of like an asshole, IE flooring it more often, being a bit more aggressive on the interstate, doing 80 instead of 70-75 I get 13mpg. Found that driving gingerly really doesn't get you much better mpg's.

 

Ran a tank of 92 Octane last month and saw no change in MPG. The price cost difference is not worth the only benefit of maybe a quieter engine.

I’ll ask this question again: Has anyone bought and used the OCTANE BOOST JUGS from an auto store?
This seems like the least expensive method to BOOST OCTANE at a lower cost than the gas station.

 

They arent worth it. Every octane point increase they advertise is just that. 1 point equals 0.1 octane

 

BTW. Trivia for you all. Go and pick up a gallon of Toulene if you can find it. One of the best true octane boosters around if you have a detonation issue and cant find high octane fuel.

I cant remember how much to use, but it was more than you would think.

I wouldnt run it in a new rig, that stuff will wreak havoc on rubber bits.

 

87 in the tundra
91 in the GTI

 

I use the left button. Might experiment next week when my DAP tune arrives

 

I have not noticed my engine being loud, when I run 87/93 seems about the same, or my radio is to loud. One thing I am loving is these gas prices $2.37 regular in East Texas

 

What??? Can’t hear you!

 

Someone made a comment the 5.7 engine making a loud noise, I don’t think my does

 

My understanding is the varnish is from non e fuel and the ethanol puts it in suspension. When e fuel breaks down it is something called phase separation and Does so much faster than non e fuel.

 

Yes.

What many don’t understand is modern engines adjust (reduce) timing for this detonation and when they do......bam! Less power! So less detonation would allow timing to be advanced more which equals more power.

 

I try to always use premium cause it doesn’t have ethanol.

But for the more octane more power, my wife was looking at a Mazda CX-5 and those advertise more HP the better gas you use. I know that’s not a Toyota, but maybe it does it too.

 

Whatever is cheapest

 

Not sure gas prices are going down in East Texas and getting better mileage 19.2 mpg loving it, based off - app Fuelly

 

I made a 6 hour round trip this weekend. Got 13.9mpg on the way there with 87 Octane. Truck was on E when I got there. Filled up with 91 octane and averaged 16.7 on the way home and that’s pulling a head wind with a new KTM in the bed.

 

we have 87-89-93. I use the 89.

 

How? Programmer? I get 14-15 City and 17-19 Highway.

 

Getting 10mpg city towing and hauling heavy.

 

Actually before you jump me for what I wrote re read what I wrote. 87 octane fuel as a whole is shit gas. If youre going to tell me Im full of shit using 93 Octane fuel in everything I own then I invite you spend a month or 2 or or 4 or more setting up as many tests as you feel necessary to prove to this forum and all its members that Im full of shit for using 93 Ethanol gas. According to your statement nothing I have in my shop runs, 2 stroke or 4 stoke , small engime or large engine left for 30 days untouched. I can leave my boat for 6 months with 93 octane and a 2 stroke Yamaha 130 hp and walk up and it fire right off and haul ass out 40 miles offshore Cape Canaveral and back with absolutely zero issues whatsoever. I live it and breathe it in everything I own.....93 Ethonal gas! You couldnt pay me to 87 ethanol gas!

 

So you're saying that its octane rating that causes varnish and ruins float needles etc? This I gotta hear. Please explain it.

 

I really have to have my truck checked out. I reset and it did 9mpg now. I don't beat on it and don't tow anything.

 

Let me know what you find out. My 02’ gets maybe 12-13 regular driving. I don’t do much highway driving so maybe thats why? She might need a long highway trip to burn off the old dust.