Gas Octane

87 when not towing/ around town...93 for towing and highways runs

 

yes I know the difference. pre ignition melts parts detonation blows parts into pieces I know detonation happens after combustion I was trying to bring it down to lamence terms for the less mechanically inclined. I prolly used the wrong terms then I should have but no matter what terms you use the result is the same a higher compression engine can ignite with out a spark because it seperates the H from C in HC (hydrocarbon-also know as gas) with the compression. higher octane gas prevents this by making the H and C chemical bond stronger to where it requires a spark to combust. there it is in non lamence terms

 

and what you are talking about is calculated horsepower. it is what the horsepower could be in perfect conditions but no one usually even looks at this numbe unless you are trying to sell an engine to someone across the country where there weather conditions are wrong.
I do know we can dyno a nascar engine at 60 degrees F and get 900 hp (round numbers) and come back the next day at 50 degrees F and have 910 hp
moral of the story no correction factor

 

layman's terms

 

Lamence

NASCAR tech don't English.

 

all has ethanol in town. When you get out of town you can find 87 without but higher has ethanol. Ethanol is used to increase the octane. It sucks because I like to run non-ethanol in boat but it takes 93. Some of the diffs that people see in MPGs could be dur to ethanol content

 

you trying go blow that thing up? As far as the ethanol sticker placement on the pump it just happens to be near the 87 nozzle because that is where they put it. Since I own an older outboard running high compression I have done a lot of reading on ethanol and the impact on outboard motors. A lot of people around here who are serious about their boats use ethanol test kits. I can tell you most all premium has ethanol even at stations that sell ethanol free regular. Mid grade is a blend of the 2 at the pump.

 

Lol so I can't spell "laymans"
And yes NASCAR don't "teach" English

 

NASCAR == Redneck

 

LMAO!!! That has to be one of the best excuses yet.

Yeah, I always give incorrect information and contradict myself when I'm trying to make it easier for others to understand and I ALWAYS tell everyone how smart I am while I'm doing it. Mmhmm, sure you really knew the difference. Still LMAO!!!

 

Agree with Brunes, I'll through a tank of the 91/93 for road trips or what not.

 

Minimum 91 octane is what's recommended by Toyota in my manual... I trust Toyota over a bunch of yahoo's and I own mine so I want it to last

 

I'm willing to bet money your manual does NOT say that, go back a page and look at my post. Research octane rating and octane rating aren't the same, yours has a recommended octane rating of 87. Nobody yet has answered my question about why the recommended octane changed after 06, but since 07 it looks like toyota has been saying you only need 87.

 

Maybe Toyota stopped getting money under the table from the big oil companies.

 

Mine says 87 and up

Not 87

 

In my area 93 octane costs roughly 10% more than 87 octane. I can't precisely replicate driving conditions for each tank full, but I am relatively sure that I get 10% more miles per gallon out of the 93 (only 1.6 - 2.3 more mpg=10%) therefore I am convinced that fuel cost is at worst the same, but there may be some benefit in fuel detergents, additives, etc. So for me I can rationalize buying the higher octane stuff.

 

An engine that was designed to run on a lower octane fuel can actually suffer with higher octane. The higher octane RETARDS the ignition to keep auto combustion from happening in high compression engines. 91 octane burns SLOWER than 87 octane.

 

^^ x2 in regards to suffer = less MPGs.

On a modern ECU setup like my 03 IS300, the MPGs and perfomance increases with higher octane as the ECU's closed loop ignition probing and knock sensing advances the timing to use it. On the flip side its not dangerous to run the lower octane, the mapping adapts- to an extent. If you have an old engine with build-up and/or pushing it really hard, retarding timing can only go so far but can't prevent pre-ignition.

On my 5vzfe, I get better mileage using 87. The ECU is 'dumber' to knock feedback and the OE compression and ECU's ignition curve is more suited for 87 and doesn't benifit from higher octane. So if I'm not boosting (road trip), I'll fill up on that. Once I revamp the water/meth to be more accurate, I may always run 87. Boost on the other hand- I have a ping happy 5vz, 91 without water/meth barely does the job even with a piggy that keeps good a/fs and retards timing. E85 tells ping to f*ck off and I can run the OE ECU's N/A timing curve, and could probably advance it if I had the ability.

 

Changing octane from a vehicle that calls for 91 and you put in 87 will hurt performance. Tacoma running 87 236HP 266 FPT, 91 gets you 239HP and 278 FPT. No much improvement except torque. 91 and 93 oct, has advantages over 87 except cost. Running higher oct does little for your vehicle but I have read nurmerous posting on here and in articles and seen little where it MAY harm your vehicle and none hurting performance.

 

I've noticed a difference from 87 to 93. Its not just the butt dyno either. I've had a friend of mine put gas in my taco, and id get my truck back, and definitely notice its not 93...