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What gas are you using?

What Octane?


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Dirt

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Almost always top tier. The book says 87 so that's what I use unless in the areas that only sell 85. Haven't had any problems with the gas in 16K miles. Cold weather and winter tires knock down mileage, but the Taco runs just fine. Now that I've read these comments, I'll try 91 for a few tanks when the weather breaks and season changes.
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izzy

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The only tank of 87 my truck ever had was when the dealership filled it up when I bought it.

Since tank 1 it's been on Top Tier 91.

No reason to not use the highest octane fuel you can in a turbo engine. Zero downsides, only upsides, better knock protection, and more power.

Your rods and bottom end and piston crowns will thank you :like:
 

Will721

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Newer engines aren't really going to experience detonation reguardless. Newer computers and knock sensors do a great job negating it. To the point that older engines with efi didn't see near the hp increase switching fuel octanes without a tune, while new engines have an observable and measurable change in hp and tq.

Personally running 89 octane e15 cause its cheap. Still maintaining around 20mpg mixed with cold midwest temps. Actually got 18mpg on the interstate the other day, but that was also in 4x4 driving through a blizzard. Typical highway flat ground is around 24mpg, 17-18mpg city. Plus ethanol is actually better in winter as it is hydroscopic. Which is why water contamination isn't nearly as prevalent as it used to be. HEET, which everyone for some reason still loves to this day, was just isopropyl alcohol.
 

Yotota

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91 high detergent brand Shell &/or Chevron
I can tell the difference with 91
I'm 100% of the same opinion.

It's been proven that the T24A-FTS in our trucks is tuned for higher than 87 octane. This is evident because the engine produces more power on the dyno with 92 octane pump gas, than it does with 87 octane. If the engine was "only" tuned for 87 octane, there would be no difference in power. Instead, the ECU must be adding timing and possibly boost to generate that power; ergo, the ECU is technically PULLING timing/boost from the baseline while running 87 octane to prevent detonation.
 

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izzy

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Newer engines aren't really going to experience detonation reguardless
They will and do.

New gas turbo engines will absolutely knock themselves to death.

It's probably more likely than ever due to everyone going high compression + forced induction (T24A-FTS has a 11:1 compression ratio). That's a lot of squeeze before you add any boost.

Also the go-to super lean tune + stroked out undersquare setups are all rod bending recipes.

In my opinion, Toyota should have made these a 2.7 and turned the boost and base comp down. Makes no sense to not go as large as you can displacement wise and then add boost.

As a comparison my EJ 255 base comp is 8.4:1. Lots of overhead to add boost and less risk of LSPI and detonation. Out of boost its not fast, but that is how turbo engines work.

Everything wrong with modern DI gas turbo engines is because consumers are allergic to turbo lag. They must be able to race from stop light to stop light like idiots. When you make a gas turbo engine emulate a diesel (which the T24A-FTS is doing) you get the worst of both.
 

Glizzy

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I'm tuned, using 91 octane. I'd recommend always using normal pump fuel with 10% ethanol as it helps with detonation prevention. Ethanol-free fuel will make a modern turbocharged vehicle knock its head off.
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