Compression of our motor and octane

That’s very odd and goes against logic. Low octane and low timing go hand in hand. Are you running an aftermarket intake?

 

Not really, I heard the same from other's in town that have gen3 tacoma's. Our water company still has a few sr5 v6 gen3 taco's in their fleet. They claim they run great on 87, no reason to go higher. My truck along with others are bone stock. Any grade fuel higher than 89, will make the truck run piggish. I haven't heard a single gen3 owner here say they need 92 octane fuel, it's only some here that think more is better.

 

This is illogical from an engineering aspect. Engines don’t run worse if the octane exceeds the ability of the motor to advance timing. It does not inhibit normal combustion. If you take a regular car and put race fuel in it will not make it run worse. Octane is a rating that indicates its resistance to pre-ignition, the ability of the engine to create combustion is not affected by the octane rating.

@5:39 they start talking about fuel and engine timing. https://youtu.be/v9au87Zliag

 

he says that on every octane thread. he is very against anything other than 87.

 

Got it, old dogs, new tricks…

 

FYI, on tuned engine you can get kclv value to 25-26 on 87 at moderate load without -6 -7 spikes on knock feedback. Some tunes had it at 32.
So the engine runs and performs well on 87.
Do the data log and see results. For me, if you drive stock ECU calibration, high octane doesn't worth the money.

 

we have widely-available ethanol-free 89 and 93 around here. Would the 89 be worth it? that's what i've been running in my 2.7. feels better and better MPGs than ethanol 87.

 

If it works for you and the engine performs as expected at different temps and loads.
I observed Stock ECU and most of original OVTunes( and early derivatives of it) consistently retarding timing on premium fuel under a moderate load (6th speed, 65-70 mph) due to present knocking ( mentioned KFB spikes). I was not willing to pay $10-20 per tank difference for the fuel that does not perform.

 

Thats just not entirely true. I've had other vehicles like snowmobiles, and race bikes. If the engine isn't built to run higher octane race gas, its going to perform worse with it, all the tuning isn't going to help. It's basically the same with my truck. It can't compensate well enough to run 92 octane fuel that wasn't meant for it. Yeah, it will still run, but not like it does on 87.

 

One other thing to consider for folks that don’t see improvement on 91-93 octane is if they live in an area where no one buys premium fuel. If that fuel just sits in the tank at the station, collecting water and getting old, it’s probably not an octane issue, it’s a bad gas issue.

I have data logged a lot of Toyota vehicles, 2nd Gen Tacoma, Tundra, 4Runner, and 3rd Gen Tacomas. Given that they have good, fresh fuel, they will definitely advance timing more on premium (91-93) vs. regular (85-87). This is true for stock and with the aftermarket calibrations. Whether that advance and performance is worth the cost is an individual decision, but the vehicle will advance more on premium by design. This isn’t a “new feature” of the 3rd Gen Tacoma, Toyota uses this across platforms and has done it for quite some time.

 

Running 94E0 on premium SFOB tune.

Truck drives absolutely amazing while getting stock MPGs even though my truck is modified and carrying 650# of constant weight.

On stock tune I ran 91E0, truck also drove great.

FWIW, all my Japanese brand vehicles drove better/smoother and got better gas mileage on 91E0 or higher.

 

I am interested in logging once my iOS compatible device arrives.

 

junkhead to the rescue

 

I had a 4.7 gen1 tundra that I tried running 92 octane in several times. I noticed zero difference, but at least it wasn't as drastic a change with poorer performance as in my tacoma now. We have at least 10% ethanol blended in our fuel everywhere you go.
As far as premium fuels being stale, it's possible, but I thought premium will stay fresher much longer than the regular blends. At any rate I fill up with top tier gas at a place thats always busy.

 

The interesting thing is a lot of people’s expectation of what an extra 10-20 HP “feels like”. It’s less than 5-10% of the total vehicle power. The butt dyno isn’t going to be wowed by these relatively small changes. However, these types of increases can be the difference between the truck downshifting or holding a gear in many situations. Premium fuel while towing on a hot day will definitely help the vehicle perform and tow better. Will it wow the butt dyno? Don’t know, butt dyno calibration and sensitivity has massive variability. Strapping the truck down to an actual dyno makes the results very clear.

Increasing the torque of the vehicle below 3500 rpm will be noticeable in the butt dyno, but simply adding premium fuel on the stock calibration only does so much there, having a tune that boosts torque in that range combined with the premium is where things really change for the better. These trucks really benefit from several well designed “small changes” that all add up into a greater overall package. Premium fuel is a part of those small changes. Whether your wallet wants to go down that road is a personal choice.

 

I have no need whatsoever to go down the road of a tune then needing premium fuel, when my truck runs so well on regular like others here in town. I don't tow anything much over 2k lbs anymore. Even if I did, I can't see there would be any problem whatsoever.

 

From experience, Ive found that it takes 2 tanks of 93 for the computer to fully adjust to the higher octane. After that I can get by using one tank of 87 octane in between each tank of 93. If I go with 2 tanks of 87 in a row the shuuder comes back and engine is louder and not as smooth.

 

I tried multiple tanks, it seems to get the worst during the 3rd tank. Lots of gear hunting when it came to any grade hill, plus an exhaust tip that was dark sooty black, no longer the light grayish /orange it usually has when using 87. My truck doesn't have a shudder running regular, or premium fuel. If your have shudder, imo, thats something else going on.